Observation of the rare Bs0µ+µ decay from the combined analysis of CMS and LHCb data

Journal name:
Nature
Volume:
522,
Pages:
68–72
Date published:
DOI:
doi:10.1038/nature14474
Received
Accepted
Published online

The standard model of particle physics describes the fundamental particles and their interactions via the strong, electromagnetic and weak forces. It provides precise predictions for measurable quantities that can be tested experimentally. The probabilities, or branching fractions, of the strange B meson ( ) and the B0 meson decaying into two oppositely charged muons (μ+ and μ) are especially interesting because of their sensitivity to theories that extend the standard model. The standard model predicts that the and decays are very rare, with about four of the former occurring for every billion mesons produced, and one of the latter occurring for every ten billion B0 mesons1. A difference in the observed branching fractions with respect to the predictions of the standard model would provide a direction in which the standard model should be extended. Before the Large Hadron Collider (LHC) at CERN2 started operating, no evidence for either decay mode had been found. Upper limits on the branching fractions were an order of magnitude above the standard model predictions. The CMS (Compact Muon Solenoid) and LHCb (Large Hadron Collider beauty) collaborations have performed a joint analysis of the data from proton–proton collisions that they collected in 2011 at a centre-of-mass energy of seven teraelectronvolts and in 2012 at eight teraelectronvolts. Here we report the first observation of the µ+µ decay, with a statistical significance exceeding six standard deviations, and the best measurement so far of its branching fraction. Furthermore, we obtained evidence for the µ+µ decay with a statistical significance of three standard deviations. Both measurements are statistically compatible with standard model predictions and allow stringent constraints to be placed on theories beyond the standard model. The LHC experiments will resume taking data in 2015, recording proton–proton collisions at a centre-of-mass energy of 13 teraelectronvolts, which will approximately double the production rates of and B0 mesons and lead to further improvements in the precision of these crucial tests of the standard model.

At a glance

Figures

  1. Feynman diagrams related to the [rarr][mu]+[mu]- decay.
    Figure 1: Feynman diagrams related to the right arrowμ+μ decay.

    a, π+ meson decay through the charged-current process; b, B+ meson decay through the charged-current process; c, a decay through the direct flavour changing neutral current process, which is forbidden in the SM, as indicated by a large red ‘X’; d, e, higher-order flavour changing neutral current processes for the decay allowed in the SM; and f and g, examples of processes for the same decay in theories extending the SM, where new particles, denoted X0 and X+, can alter the decay rate.

  2. Weighted distribution of the dimuon invariant mass, m[mu]+[mu]-, for all categories.
    Figure 2: Weighted distribution of the dimuon invariant mass, mμ+μ, for all categories.

    Superimposed on the data points in black are the combined fit (solid blue line) and its components: the (yellow shaded area) and B0 (light-blue shaded area) signal components; the combinatorial background (dash-dotted green line); the sum of the semi-leptonic backgrounds (dotted salmon line); and the peaking backgrounds (dashed violet line). The horizontal bar on each histogram point denotes the size of the binning, while the vertical bar denotes the 68% confidence interval. See main text for details on the weighting procedure.

  3. Likelihood contours in the (B0[rarr][mu]+[mu]-) versus [rarr][mu]+[mu]-) plane.
    Figure 3: Likelihood contours in the (B0right arrowμ+μ) versus right arrowμ+μ) plane.

    The (black) cross in a marks the best-fit central value. The SM expectation and its uncertainty is shown as the (red) marker. Each contour encloses a region approximately corresponding to the reported confidence level. b, c, Variations of the test statistic 2ΔlnL for (b) and (B0 right arrow µ+µ) (c). The dark and light (cyan) areas define the ±1σ and ±2σ confidence intervals for the branching fraction, respectively. The SM prediction and its uncertainty for each branching fraction is denoted with the vertical (red) band.

  4. Variation of the test statistic -2[Dgr]lnL as a function of the ratio of branching fractions [rarr][mu]+[mu]-)/[rarr][mu]+[mu]-).
    Figure 4: Variation of the test statistic 2ΔlnL as a function of the ratio of branching fractions right arrowμ+μ)/ right arrowμ+μ).

    The dark and light (cyan) areas define the ±1σ and ±2σ confidence intervals for , respectively. The value and uncertainty for predicted in the SM, which is the same in BSM theories with the minimal flavour violation (MFV) property, is denoted with the vertical (red) band.

  5. Distribution of the dimuon invariant mass m[mu]+[mu]- in each of the 20 categories.
    Extended Data Fig. 1: Distribution of the dimuon invariant mass mμ+μ in each of the 20 categories.

    Superimposed on the data points in black are the combined fit (solid blue) and its components: the (yellow shaded) and B0 (light-blue shaded) signal components; the combinatorial background (dash-dotted green); the sum of the semi-leptonic backgrounds (dotted salmon); and the peaking backgrounds (dashed violet). The categories are defined by the range of BDT values for LHCb, and for CMS, by centre-of-mass energy, by the region of the detector in which the muons are detected, and by the range of BDT values. Categories for which both muons are detected in the central region of the CMS detector are denoted with CR, those for which at least one muon was detected into the forward region with FR.

  6. Distribution of the dimuon invariant mass m[mu]+[mu]- for the best six categories.
    Extended Data Fig. 2: Distribution of the dimuon invariant mass mμ+μ for the best six categories.

    Categories are ranked according to values of S/(S + B) where S and B are the numbers of signal events expected assuming the SM rates and background events under the peak for a given category, respectively. The mass distribution for the six highest-ranking categories, three per experiment, is shown. Superimposed on the data points in black are the combined full fit (solid blue) and its components: the (yellow shaded) and B0 (light-blue shaded) signal components; the combinatorial background (dash-dotted green); the sum of the semi-leptonic backgrounds (dotted salmon); and the peaking backgrounds (dashed violet).

  7. Schematic of the CMS detector and event display for a candidate [rarr][mu]+[mu]- decay at CMS.
    Extended Data Fig. 3: Schematic of the CMS detector and event display for a candidate right arrowμ+μ decay at CMS.

    a, The CMS detector and its components; see ref. 20 for details. b, A candidate decay produced in proton–proton collisions at 8 TeV in 2012 and recorded in the CMS detector. The red arched curves represent the trajectories of the muons from the decay candidate.

  8. Schematic of the LHCb detector and event display for a candidate [rarr][mu]+[mu]- decay at LHCb.
    Extended Data Fig. 4: Schematic of the LHCb detector and event display for a candidate right arrowμ+μ decay at LHCb.

    a, The LHCb detector and its components; see ref. 21 for details. b, A candidate decay produced in proton–proton collisions at 7 TeV in 2011 and recorded in the LHCb detector. The proton–proton collision occurs on the left-hand side, at the origin of the trajectories depicted with the orange curves. The red curves represent the trajectories of the muons from the candidate decay.

  9. Confidence level as a function of the (B0[rarr][mu]+[mu]-) hypothesis.
    Extended Data Fig. 5: Confidence level as a function of the (B0right arrowμ+μ) hypothesis.

    The value of 1 − CL, where CL is the confidence level obtained with the Feldman–Cousins procedure, as a function of (B0 right arrow µ+µ) is shown in logarithmic scale. The points mark the computed 1 − CL values and the curve is their spline interpolation. The dark and light (cyan) areas define the two-sided ±1σ and ±2σ confidence intervals for the branching fraction, while the dashed horizontal line defines the confidence level for the 3σ one-sided interval. The dashed (grey) curve shows the 1 − CL values computed from the one-dimensional −2ΔlnL test statistic using Wilks’ theorem. Deviations between these confidence level values and those from the Feldman–Cousins procedure30 illustrate the degree of approximation implied by the asymptotic assumptions inherent to Wilks’ theorem29.

  10. Likelihood contours for the ratios of the branching fractions with respect to their SM prediction, in the  versus  plane.
    Extended Data Fig. 6: Likelihood contours for the ratios of the branching fractions with respect to their SM prediction, in the versus plane.

    a, The (black) cross marks the central value returned by the fit. The SM point is shown as the (red) square located, by construction, at . Each contour encloses a region approximately corresponding to the reported confidence level. The SM branching fractions are assumed uncorrelated to each other, and their uncertainties are accounted for in the likelihood contours. b, c, Variations of the test statistic 2ΔlnL for and are shown in b and c, respectively. The SM is represented by the (red) vertical lines. The dark and light (cyan) areas define the ±1σ and ±2σ confidence intervals, respectively.

  11. Search for the [rarr][mu]+[mu]- and B0[rarr][mu]+[mu]-decays, reported by 11 experiments spanning more than three decades, and by the present results.
    Extended Data Fig. 7: Search for the right arrowμ+μ and B0right arrowμ+μdecays, reported by 11 experiments spanning more than three decades, and by the present results.

    Markers without error bars denote upper limits on the branching fractions at 90% confidence level, while measurements are denoted with error bars delimiting 68% confidence intervals. The solid horizontal lines represent the SM predictions for the and B0 right arrow µ+µ branching fractions1; the blue (red) lines and markers relate to the (B0 right arrow µ+µ) decay. Data (see key) are from refs 17, 18, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60; for details see Methods. Inset, magnified view of the last period in time.

Main

Experimental particle physicists have been testing the predictions of the standard model of particle physics (SM) with increasing precision since the 1970s. Theoretical developments have kept pace by improving the accuracy of the SM predictions as the experimental results gained in precision. In the course of the past few decades, the SM has passed critical tests derived from experiment, but it does not address some profound questions about the nature of the Universe. For example, the existence of dark matter, which has been confirmed by cosmological data3, is not accommodated by the SM. It also fails to explain the origin of the asymmetry between matter and antimatter, which after the Big Bang led to the survival of the tiny amount of matter currently present in the Universe3, 4. Many theories have been proposed to modify the SM to provide solutions to these open questions.

The and B0 mesons are unstable particles that decay via the weak interaction. The measurement of the branching fractions of the very rare decays of these mesons into a dimuon (µ+µ) final state is especially interesting.

At the elementary level, the weak force is composed of a ‘charged current’ and a ‘neutral current’ mediated by the W± and Z0 bosons, respectively. An example of the charged current is the decay of the π+ meson, which consists of an up (u) quark of electrical charge +2/3 of the charge of the proton and a down (d) antiquark of charge +1/3. A pictorial representation of this process, known as a Feynman diagram, is shown in Fig. 1a. The u and d quarks are ‘first generation’ or lowest mass quarks. Whenever a decay mode is specified in this Letter, the charge conjugate mode is implied.

Figure 1: Feynman diagrams related to the right arrowμ+μ decay.
Feynman diagrams related to the [rarr][mu]+[mu]- decay.

a, π+ meson decay through the charged-current process; b, B+ meson decay through the charged-current process; c, a decay through the direct flavour changing neutral current process, which is forbidden in the SM, as indicated by a large red ‘X’; d, e, higher-order flavour changing neutral current processes for the decay allowed in the SM; and f and g, examples of processes for the same decay in theories extending the SM, where new particles, denoted X0 and X+, can alter the decay rate.

The B+ meson is similar to the π+, except that the light d antiquark is replaced by the heavy ‘third generation’ (highest mass quarks) beauty (b) antiquark, which has a charge of +1/3 and a mass of ~5 GeV/c2 (about five times the mass of a proton). The decay B+right arrow µ+ν, represented in Fig. 1b, is allowed but highly suppressed because of angular momentum considerations (helicity suppression) and because it involves transitions between quarks of different generations (CKM suppression), specifically the third and first generations of quarks. All b hadrons, including the B+, and B0 mesons, decay predominantly via the transition of the b antiquark to a ‘second generation’ (intermediate mass quarks) charm (c) antiquark, which is less CKM suppressed, into final states with charmed hadrons. Many allowed decay modes, which typically involve charmed hadrons and other particles, have angular momentum configurations that are not helicity suppressed.

The neutral meson is similar to the B+ except that the u quark is replaced by a second generation strange (s) quark of charge −1/3. The decay of the meson to two muons, shown in Fig. 1c, is forbidden at the elementary level because the Z0 cannot couple directly to quarks of different flavours, that is, there are no direct ‘flavour changing neutral currents’. However, it is possible to respect this rule and still have this decay occur through ‘higher order’ transitions such as those shown in Fig. 1d and e. These are highly suppressed because each additional interaction vertex reduces their probability of occurring significantly. They are also helicity and CKM suppressed. Consequently, the branching fraction for the decay is expected to be very small compared to the dominant b antiquark to c antiquark transitions. The corresponding decay of the B0 meson, where a d quark replaces the s quark, is even more CKM suppressed because it requires a jump across two quark generations rather than just one.

The branching fractions, , of these two decays, accounting for higher-order electromagnetic and strong interaction effects, and using lattice quantum chromodynamics to compute the and B0 meson decay constants5, 6, 7, are reliably calculated1 in the SM. Their values are and .

Many theories that seek to go beyond the standard model (BSM) include new phenomena and particles8, 9, such as in the diagrams shown in Fig. 1f and g, that can considerably modify the SM branching fractions. In particular, theories with additional Higgs bosons10, 11 predict possible enhancements to the branching fractions. A significant deviation of either of the two branching fraction measurements from the SM predictions would give insight on how the SM should be extended. Alternatively, a measurement compatible with the SM could provide strong constraints on BSM theories.

The ratio of the branching fractions of the two decay modes provides powerful discrimination among BSM theories12. It is predicted in the SM (refs 1, 13 (updates available at http://itpwiki.unibe.ch/), 14, 15 (updated results and plots available at http://www.slac.stanford.edu/xorg/hfag/)) to be . Notably, BSM theories with the property of minimal flavour violation16 predict the same value as the SM for this ratio.

The first evidence for the decay was presented by the LHCb collaboration in 201217. Both CMS and LHCb later published results from all data collected in proton–proton collisions at centre-of-mass energies of 7 TeV in 2011 and 8 TeV in 2012. The measurements had comparable precision and were in good agreement18, 19, although neither of the individual results had sufficient precision to constitute the first definitive observation of the decay to two muons.

In this Letter, the two sets of data are combined and analysed simultaneously to exploit fully the statistical power of the data and to account for the main correlations between them. The data correspond to total integrated luminosities of 25 fb−1 and 3 fb−1 for the CMS and LHCb experiments, respectively, equivalent to a total of approximately 1012 and B0 mesons produced in the two experiments together. Assuming the branching fractions given by the SM and accounting for the detection efficiencies, the predicted numbers of decays to be observed in the two experiments together are about 100 for and 10 for B0 right arrow µ+µ.

The CMS20 and LHCb21 detectors are designed to measure SM phenomena with high precision and search for possible deviations. The two collaborations use different and complementary strategies. In addition to performing a broad range of precision tests of the SM and studying the newly-discovered Higgs boson22, 23, CMS is designed to search for and study new particles with masses from about 100 GeV/c2 to a few TeV/c2. Since many of these new particles would be able to decay into b quarks and many of the SM measurements also involve b quarks, the detection of b-hadron decays was a key element in the design of CMS. The LHCb collaboration has optimized its detector to study matter–antimatter asymmetries and rare decays of particles containing b quarks, aiming to detect deviations from precise SM predictions that would indicate BSM effects. These different approaches, reflected in the design of the detectors, lead to instrumentation of complementary angular regions with respect to the LHC beams, to operation at different proton–proton collision rates, and to selection of b quark events with different efficiency (for experimental details, see Methods). In general, CMS operates at a higher instantaneous luminosity than LHCb but has a lower efficiency for reconstructing low-mass particles, resulting in a similar sensitivity to LHCb for B0 or (denoted hereafter by ) mesons decaying into two muons.

Muons do not have strong nuclear interactions and are too massive to emit a substantial fraction of their energy by electromagnetic radiation. This gives them the unique ability to penetrate dense materials, such as steel, and register signals in detectors embedded deep within them. Both experiments use this characteristic to identify muons.

The experiments follow similar data analysis strategies. Decays compatible with (candidate decays) are found by combining the reconstructed trajectories (tracks) of oppositely charged particles identified as muons. The separation between genuine decays and random combinations of two muons (combinatorial background), most often from semi-leptonic decays of two different b hadrons, is achieved using the dimuon invariant mass, , and the established characteristics of -meson decays. For example, because of their lifetimes of about 1.5 ps and their production at the LHC with momenta between a few GeV/c and ~100 GeV/c, mesons travel up to a few centimetres before they decay. Therefore, the ‘decay vertex’, from which the muons originate, is required to be displaced with respect to the ‘production vertex’, the point where the two protons collide. Furthermore, the negative of the candidate’s momentum vector is required to point back to the production vertex.

These criteria, amongst others that have some ability to distinguish known signal events from background events, are combined into boosted decision trees (BDTs)24, 25, 26. A BDT is an ensemble of decision trees each placing different selection requirements on the individual variables to achieve the best discrimination between ‘signal-like’ and ‘background-like’ events. Both experiments evaluated many variables for their discriminating power and each chose the best set of about ten to be used in its respective BDT. These include variables related to the quality of the reconstructed tracks of the muons; kinematic variables such as transverse momentum (with respect to the beam axis) of the individual muons and of the candidate; variables related to the decay vertex topology and fit quality, such as candidate decay length; and isolation variables, which measure the activity in terms of other particles in the vicinity of the two muons or their displaced vertex. A BDT must be ‘trained’ on collections of known background and signal events to generate the selection requirements on the variables and the weights for each tree. In the case of CMS, the background events used in the training are taken from intervals of dimuon mass above and below the signal region in data, while simulated events are used for the signal. The data are divided into disjoint sub-samples and the BDT trained on one sub-sample is applied to a different sub-sample to avoid any bias. LHCb uses simulated events for background and signal in the training of its BDT. After training, the relevant BDT is applied to each event in the data, returning a single value for the event, with high values being more signal-like. To avoid possible biases, both experiments kept the small mass interval that includes both the and B0 signals blind until all selection criteria were established.

In addition to the combinatorial background, specific b-hadron decays, such as B0 right arrow πµ+ν where the neutrino cannot be detected and the charged pion is misidentified as a muon, or B0right arrowπ0µ+µ, where the neutral pion in the decay is not reconstructed, can mimic the dimuon decay of the mesons. The invariant mass of the reconstructed dimuon candidate for these processes (semi-leptonic background) is usually smaller than the mass of the or B0 meson because the neutrino or another particle is not detected. There is also a background component from hadronic two-body decays (peaking background) as B0right arrowK+π, when both hadrons from the decay are misidentified as muons. These misidentified decays can produce peaks in the dimuon invariant-mass spectrum near the expected signal, especially for the B0right arrowµ+µ decay. Particle identification algorithms are used to minimize the probability that pions and kaons are misidentified as muons, and thus suppress these background sources. Excellent mass resolution is mandatory for distinguishing between B0 and mesons with a mass difference of about 87 MeV/c2 and for separating them from backgrounds. The mass resolution for decays in CMS ranges from 32 to 75 MeV/c2, depending on the direction of the muons relative to the beam axis, while LHCb achieves a uniform mass resolution of about 25 MeV/c2.

The CMS and LHCb data are combined by fitting a common value for each branching fraction to the data from both experiments. The branching fractions are determined from the observed numbers, efficiency-corrected, of mesons that decay into two muons and the total numbers of mesons produced. Both experiments derive the latter from the number of observed B+right arrowJ/ψK+ decays, whose branching fraction has been precisely measured elsewhere14. Assuming equal rates for B+ and B0 production, this gives the normalization for B0 right arrow µ+µ. To derive the number of mesons from this B+ decay mode, the ratio of b quarks that form (hadronize into) B+ mesons to those that form mesons is also needed. Measurements of this ratio27, 28, for which there is additional discussion in Methods, and of the branching fraction (B+ right arrow J/ψ K+) are used to normalize both sets of data and are constrained within Gaussian uncertainties in the fit. The use of these two results by both CMS and LHCb is the only significant source of correlation between their individual branching fraction measurements. The combined fit takes advantage of the larger data sample to increase the precision while properly accounting for the correlation.

In the simultaneous fit to both the CMS and LHCb data, the branching fractions of the two signal channels are common parameters of interest and are free to vary. Other parameters in the fit are considered as nuisance parameters. Those for which additional knowledge is available are constrained to be near their estimated values by using Gaussian penalties with their estimated uncertainties while the others are free to float in the fit. The ratio of the hadronization probability into B+ and mesons and the branching fraction of the normalization channel B+right arrowJ/ψK+ are common, constrained parameters. Candidate decays are categorized according to whether they were detected in CMS or LHCb and to the value of the relevant BDT discriminant. In the case of CMS, they are further categorized according to the data-taking period, and, because of the large variation in mass resolution with angle, whether the muons are both produced at large angles relative to the proton beams (central-region) or at least one muon is emitted at small angle relative to the beams (forward-region). An unbinned extended maximum likelihood fit to the dimuon invariant-mass distribution, in a region of about ±500 MeV/c2 around the mass, is performed simultaneously in all categories (12 categories from CMS and eight from LHCb). Likelihood contours in the plane of the parameters of interest, (B0 right arrow µ+µ) versus ( ), are obtained by constructing the test statistic 2ΔlnL from the difference in log-likelihood (lnL) values between fits with fixed values for the parameters of interest and the nominal fit. For each of the two branching fractions, a one-dimensional profile likelihood scan is likewise obtained by fixing only the single parameter of interest and allowing the other to vary during the fits. Additional fits are performed where the parameters under consideration are the ratio of the branching fractions relative to their SM predictions, , or the ratio of the two branching fractions.

The combined fit result is shown for all 20 categories in Extended Data Fig. 1. To represent the result of the fit in a single dimuon invariant-mass spectrum, the mass distributions of all categories, weighted according to values of S/(S + B), where S is the expected number of signals and B is the number of background events under the peak in that category, are added together and shown in Fig. 2. The result of the simultaneous fit is overlaid. An alternative representation of the fit to the dimuon invariant-mass distribution for the six categories with the highest S/(S + B) value for CMS and LHCb, as well as displays of events with high probability to be genuine signal decays, are shown in Extended Data Figs 2, 3, 4.

Figure 2: Weighted distribution of the dimuon invariant mass, mμ+μ, for all categories.
Weighted distribution of the dimuon invariant mass, m[mu]+[mu]-, for all categories.

Superimposed on the data points in black are the combined fit (solid blue line) and its components: the (yellow shaded area) and B0 (light-blue shaded area) signal components; the combinatorial background (dash-dotted green line); the sum of the semi-leptonic backgrounds (dotted salmon line); and the peaking backgrounds (dashed violet line). The horizontal bar on each histogram point denotes the size of the binning, while the vertical bar denotes the 68% confidence interval. See main text for details on the weighting procedure.

The combined fit leads to the measurements where the uncertainties include both statistical and systematic sources, the latter contributing 35% and 18% of the total uncertainty for the and B0 signals, respectively. Using Wilks’ theorem29, the statistical significance in unit of standard deviations, σ, is computed to be 6.2 for the decay mode and 3.2 for the B0 right arrow µ+µ mode. For each signal the null hypothesis that is used to compute the significance includes all background components predicted by the SM as well as the other signal, whose branching fraction is allowed to vary freely. The median expected significances assuming the SM branching fractions are 7.4σ and 0.8σ for the and B0 modes, respectively. Likelihood contours for (B0 right arrow µ+µ) versus are shown in Fig. 3. One-dimensional likelihood scans for both decay modes are displayed in the same figure. In addition to the likelihood scan, the statistical significance and confidence intervals for the B0 branching fraction are determined using simulated experiments. This determination yields a significance of 3.0σ for a B0 signal with respect to the same null hypothesis described above. Following the Feldman–Cousins30 procedure, ±1σ and ±2σ confidence intervals for (B0 right arrow µ+µ) of [2.5, 5.6] × 10−10 and [1.4, 7.4] × 10−10 are obtained, respectively (see Extended Data Fig. 5).

Figure 3: Likelihood contours in the (B0right arrowμ+μ) versus right arrowμ+μ) plane.
Likelihood contours in the (B0[rarr][mu]+[mu]-) versus [rarr][mu]+[mu]-) plane.

The (black) cross in a marks the best-fit central value. The SM expectation and its uncertainty is shown as the (red) marker. Each contour encloses a region approximately corresponding to the reported confidence level. b, c, Variations of the test statistic 2ΔlnL for (b) and (B0 right arrow µ+µ) (c). The dark and light (cyan) areas define the ±1σ and ±2σ confidence intervals for the branching fraction, respectively. The SM prediction and its uncertainty for each branching fraction is denoted with the vertical (red) band.

The fit for the ratios of the branching fractions relative to their SM predictions yields . Associated likelihood contours and one-dimensional likelihood scans are shown in Extended Data Fig. 6. The measurements are compatible with the SM branching fractions of the and B0 right arrow µ+µ decays at the 1.2σ and 2.2σ level, respectively, when computed from the one-dimensional hypothesis tests. Finally, the fit for the ratio of branching fractions yields which is compatible with the SM at the 2.3σ level. The one-dimensional likelihood scan for this parameter is shown in Fig. 4.

Figure 4: Variation of the test statistic 2ΔlnL as a function of the ratio of branching fractions right arrowμ+μ)/ right arrowμ+μ).
Variation of the test statistic -2[Dgr]lnL as a function of the ratio of branching fractions [rarr][mu]+[mu]-)/[rarr][mu]+[mu]-).

The dark and light (cyan) areas define the ±1σ and ±2σ confidence intervals for , respectively. The value and uncertainty for predicted in the SM, which is the same in BSM theories with the minimal flavour violation (MFV) property, is denoted with the vertical (red) band.

The combined analysis of data from CMS and LHCb, taking advantage of their full statistical power, establishes conclusively the existence of the decay and provides an improved measurement of its branching fraction. This concludes a search that started more than three decades ago (see Extended Data Fig. 7), and initiates a phase of precision measurements of the properties of this decay. It also produces three standard deviation evidence for the B0 right arrow µ+µ decay. The measured branching fractions of both decays are compatible with SM predictions. This is the first time that the CMS and LHCb collaborations have performed a combined analysis of sets of their data in order to obtain a statistically significant observation.

Methods

Experimental setup

At the Large Hadron Collider (LHC), two counter-rotating beams of protons, contained and guided by superconducting magnets spaced around a 27 km circular tunnel, located approximately 100 m underground near Geneva, Switzerland, are brought into collision at four interaction points (IPs). The study presented in this Letter uses data collected at energies of 3.5 TeV per beam in 2011 and 4 TeV per beam in 2012 by the CMS and LHCb experiments located at two of these IPs.

The CMS and LHCb detectors are both designed to look for phenomena beyond the SM (BSM), but using complementary strategies. The CMS detector20, shown in Extended Data Fig. 3, is optimized to search for yet unknown heavy particles, with masses ranging from 100 GeV/c2 to a few TeV/c2, which, if observed, would be a direct manifestation of BSM phenomena. Since many of the hypothesized new particles can decay into particles containing b quarks or into muons, CMS is able to detect efficiently and study B0 (5,280 MeV/c2) and (5,367 MeV/c2) mesons decaying to two muons even though it is designed to search for particles with much larger masses. The CMS detector covers a very large range of angles and momenta to reconstruct high-mass states efficiently. To that extent, it employs a 13 m long, 6 m diameter superconducting solenoid magnet, operated at a field of 3.8 T, centred on the IP with its axis along the beam direction and covering both hemispheres. A series of silicon tracking layers, consisting of silicon pixel detectors near the beam and silicon strips farther out, organized in concentric cylinders around the beam, extending to a radius of 1.1 m and terminated on each end by planar detectors (disks) perpendicular to the beam, measures the momentum, angles, and position of charged particles emerging from the collisions. Tracking coverage starts from the direction perpendicular to the beam and extends to within 220 mrad from it on both sides of the IP. The inner three cylinders and disks extending from 4.3 to 10.7 cm in radius transverse to the beam are arrays of 100 × 150 µm2 silicon pixels, which can distinguish the displacement of the b-hadron decays from the primary vertex of the collision. The silicon strips, covering radii from 25 cm to approximately 110 cm, have pitches ranging from 80 to 183 µm. The impact parameter is measured with a precision of 10 µm for transverse momenta of 100 GeV/c and 20 µm for 10 GeV/c. The momentum resolution, provided mainly by the silicon strips, changes with the angle relative to the beam direction, resulting in a mass resolution for decays that varies from 32 MeV/c2 for mesons produced perpendicularly to the proton beams to 75 MeV/c2 for those produced at small angles relative to the beam direction. After the tracking system, at a greater distance from the IP, there is a calorimeter that stops (absorbs) all particles except muons and measures their energies. The calorimeter consists of an electromagnetic section followed by a hadronic section. Muons are identified by their ability to penetrate the calorimeter and the steel return yoke of the solenoid magnet and to produce signals in gas-ionization particle detectors located in compartments within the steel yoke. The CMS detector has no capability to discriminate between charged hadron species, pions, kaons, or protons, that is effective at the typical particle momenta in this analysis.

The primary commitment of the LHCb collaboration is the study of particle–antiparticle asymmetries and of rare decays of particles containing b and c quarks. LHCb aims at detecting BSM particles indirectly by measuring their effect on b-hadron properties for which precise SM predictions exist. The production cross section of b hadrons at the LHC is particularly large at small angles relative to the colliding beams. The small-angle region also provides advantages for the detection and reconstruction of a wide range of their decays. The LHCb experiment21, shown in Extended Data Fig. 4, instruments the angular interval from 10 to 300 mrad with respect to the beam direction on one side of the interaction region. Its detectors are designed to reconstruct efficiently a wide range of b-hadron decays, resulting in charged pions and kaons, protons, muons, electrons, and photons in the final state. The detector includes a high-precision tracking system consisting of a silicon strip vertex detector, a large-area silicon strip detector located upstream of a dipole magnet characterized by a field integral of 4 T m, and three stations of silicon strip detectors and straw drift tubes downstream of the magnet. The vertex detector has sufficient spatial resolution to distinguish the slight displacement of the weakly decaying b hadron from the primary production vertex where the two protons collided and produced it. The tracking detectors upstream and downstream of the dipole magnet measure the momenta of charged particles. The combined tracking system provides a momentum measurement with an uncertainty that varies from 0.4% at 5 GeV/c to 0.6% at 100 GeV/c. This results in an invariant-mass resolution of 25 MeV/c2 for mesons decaying to two muons that is nearly independent of the angle with respect to the beam. The impact parameter resolution is smaller than 20 µm for particle tracks with large transverse momentum. Different types of charged hadrons are distinguished by information from two ring-imaging Cherenkov detectors. Photon, electron, and hadron candidates are identified by calorimeters. Muons are identified by a system composed of alternating layers of iron and multiwire proportional chambers.

Neither CMS nor LHCb records all the interactions occurring at its IP because the data storage and analysis costs would be prohibitive. Since most of the interactions are reasonably well characterized (and can be further studied by recording only a small sample of them) specific event filters (known as triggers) select the rare processes that are of interest to the experiments. Both CMS and LHCb implement triggers that specifically select events containing two muons. The triggers of both experiments have a hardware stage, based on information from the calorimeter and muon systems, followed by a software stage, consisting of a large computing cluster that uses all the information from the detector, including the tracking, to make the final selection of events to be recorded for subsequent analysis. Since CMS is designed to look for much heavier objects than mesons, it selects events that contain muons with higher transverse momenta than those selected by LHCb. This eliminates many of the decays while permitting CMS to run at a higher proton–proton collision rate to look for the more rare massive particles. Thus CMS runs at higher collision rates but with lower efficiency than LHCb for mesons decaying to two muons. The overall sensitivity to these decays turns out to be similar in the two experiments.

CMS and LHCb are not the only collaborations to have searched for and B0right arrow µ+ µ decays. Over three decades, a total of eleven collaborations have taken part in this search14, as illustrated by Extended Data Fig. 7. This plot gathers the results from CLEO31, 32, 33, 34, 35, ARGUS36, UA137, 38, CDF39, 40, 41, 42, 43, 44, L345, DØ46, 47, 48, 49, 50, Belle51, Babar52, 53, LHCb17, 54, 55, 56, 57 CMS18, 58, 59 and ATLAS60.

Analysis description

The analysis techniques used to obtain the results presented in this Letter are very similar to those used to obtain the individual result in each collaboration, described in more detail in refs 18, 19. Here only the main analysis steps are reviewed and the changes used in the combined analysis are highlighted. Data samples for this analysis were collected by the two experiments in proton–proton collisions at a centre-of-mass energy of 7 and 8 TeV during 2011 and 2012, respectively. These samples correspond to a total integrated luminosity of 25 and 3 fb−1 for the CMS and LHCb experiments, respectively, and represent their complete data sets from the first running period of the LHC.

The trigger criteria were slightly different between the two experiments. The large majority of events were triggered by requirements on one or both muons of the signal decay: the LHCb detector triggered on muons with transverse momentum pT > 1.5 GeV/c while the CMS detector, because of its geometry and higher instantaneous luminosity, triggered on two muons with pT > 4(3) GeV/c, for the leading (sub-leading) muon.

The data analysis procedures in the two experiments follow similar strategies. Pairs of high-quality oppositely charged particle tracks that have one of the expected patterns of hits in the muon detectors are fitted to form a common vertex in three dimensions, which is required to be displaced from the primary interaction vertex (PV) and to have a small χ2 in the fit. The resulting candidate is further required to point back to the PV, for example, to have a small impact parameter, consistent with zero, with respect to it. The final classification of data events is done in categories of the response of a multivariate discriminant (MVA) combining information from the kinematics and vertex topology of the events. The type of MVA used is a boosted decision tree (BDT)24, 25, 26. The branching fractions are then obtained by a fit to the dimuon invariant mass, , of all categories simultaneously.

The signals appear as peaks at the and B0 masses in the invariant-mass distributions, observed over background events. One of the components of the background is combinatorial in nature, as it is due to the random combinations of genuine muons. These produce a smooth dimuon mass distribution in the vicinity of the and B0 masses, estimated in the fit to the data by extrapolation from the sidebands of the invariant-mass distribution. In addition to the combinatorial background, certain specific b-hadron decays can mimic the signal or contribute to the background in its vicinity. In particular, the semi-leptonic decays B0 right arrow πµ+ν, right arrow Kµ+ν, and can have reconstructed masses that are near the signal if one of the hadrons is misidentified as a muon and is combined with a genuine muon. Similarly the dimuon coming from the rare B0 right arrow π0µ+µ and B+ right arrow π+µ+µ decays can also fake the signal. All these background decays, when reconstructed as a dimuon final state, have invariant masses that are lower than the masses of the B0 and mesons, because they are missing one of the original decay particles. An exception is the decay , which can also populate, with a smooth mass distribution, higher-mass regions. Furthermore, background due to misidentified hadronic two-body decays , where or K, is present when both hadrons are misidentified as muons. These misidentified decays produce an apparent dimuon invariant-mass peak close to the B0 mass value. Such a peak can mimic a B0 right arrow µ+µ signal and is estimated from control channels and added to the fit.

The distributions of signal in the invariant mass and in the MVA discriminant are derived from simulations with a detailed description of the detector response for CMS and are calibrated using exclusive two-body hadronic decays in data for LHCb. The distributions for the backgrounds are obtained from simulation with the exception of the combinatorial background. The latter is obtained by interpolating from the data invariant-mass sidebands separately for each category, after the subtraction of the other background components.

To compute the signal branching fractions, the numbers of and B0 mesons that are produced, as well as the numbers of those that have decayed into a dimuon pair, are needed. The latter numbers are the raw results of this analysis, whereas the former need to be determined from measurements of one or more ‘normalization’ decay channels, which are abundantly produced, have an absolute branching fraction that is already known with good precision, and that share characteristics with the signals, so that their trigger and selection efficiencies do not differ significantly. Both experiments use the B+ right arrow J/ψK+ decay as a normalization channel with (B+ right arrow J/ψ (µ+µ) K+) = (6.10 ± 0.19) × 10−5, and LHCb also uses the B0 right arrow K+π channel with (B0 right arrow K+π) = (1.96 ± 0.05) × 10−5. Both branching fraction values are taken from ref. 14. Hence, the right arrow µ+µ branching fraction is expressed as a function of the number of signal events in the data normalized to the numbers of B+ right arrow J/ψK+ and B0 right arrow K+π events:

where the ‘norm.’ subscript refers to either of the normalization channels. The values of the normalization parameter αnorm. obtained by LHCb from the two normalization channels are found in good agreement and their weighted average is used. In this formula ε indicates the total event detection efficiency including geometrical acceptance, trigger selection, reconstruction, and analysis selection for the corresponding decay. The fd/fs factor is the ratio of the probabilities for a b quark to hadronize into a B0 as compared to a meson; the probability to hadronize into a B+ (fu) is assumed to be equal to that into B0 (fd) on the basis of theoretical grounds, and this assumption is checked on data. The value of fd/fs = 3.86 ± 0.22 measured by LHCb27, 28, 61 is used in this analysis. As the value of fd/fs depends on the kinematic range of the considered particles, which differs between LHCb and CMS, CMS checked this observable with the decays and B+ right arrow J/ψK+ within its acceptance, finding a consistent value. An additional systematic uncertainty of 5% was assigned to fd/fs to account for the extrapolation of the LHCb result to the CMS acceptance. An analogous formula to that in equation (1) holds for the normalization of the B0 right arrow µ+µ decay, with the notable difference that the fd/fs factor is replaced by fd/fu = 1.

The antiparticle and the particle B0 ( ) can both decay into two muons and no attempt is made in this analysis to determine whether the antiparticle or particle was produced (untagged method). However, the B0 and particles are known to oscillate, that is to transform continuously into their antiparticles and vice versa. Therefore, a quantum superposition of particle and antiparticle states propagates in the laboratory before decaying. This superposition can be described by two ‘mass eigenstates’, which are symmetric and antisymmetric in the charge-parity (CP) quantum number, and have slightly different masses. In the SM, the heavy eigenstate can decay into two muons, whereas the light eigenstate cannot without violating the CP quantum number conservation. In BSM models, this is not necessarily the case. In addition to their masses, the two eigenstates of the system also differ in their lifetime values14. The lifetimes of the light and heavy eigenstates are also different from the average lifetime, which is used by CMS and LHCb in the simulations of signal decays. Since the information on the displacement of the secondary decay with respect to the PV is used as a discriminant against combinatorial background in the analysis, the efficiency versus lifetime has a model-dependent bias62 that must be removed. This bias is estimated assuming SM dynamics. Owing to the smaller difference between the lifetime of its heavy and light mass eigenstates, no correction is required for the B0 decay mode.

Detector simulations are needed by both CMS and LHCb. CMS relies on simulated events to determine resolutions and trigger and reconstruction efficiencies, and to provide the signal sample for training the BDT. The dimuon mass resolution given by the simulation is validated using data on J/ψ, Υ, and Z-boson decays to two muons. The tracking and trigger efficiencies obtained from the simulation are checked using special control samples from data. The LHCb analysis is designed to minimize the impact of discrepancies between simulations and data. The mass resolution is measured with data. The distribution of the BDT for the signal and for the background is also calibrated with data using control channels and mass sidebands. The efficiency ratio for the trigger is also largely determined from data. The simulations are used to determine the efficiency ratios of selection and reconstruction processes between signal and normalization channels. As for the overall detector simulation, each experiment has a team dedicated to making the simulations as complete and realistic as possible. The simulated data are constantly being compared to the actual data. Agreement between simulation and data in both experiments is quite good, often extending well beyond the cores of distributions. Differences occur because, for example, of incomplete description of the material of the detectors, approximations made to keep the computer time manageable, residual uncertainties in calibration and alignment, and discrepancies or limitations in the underlying theory and experimental data used to model the relevant collisions and decays. Small differences between simulation and data that are known to have an impact on the result are treated either by reweighting the simulations to match the data or by assigning appropriate systematic uncertainties.

Small changes are made to the analysis procedure with respect to refs 18, 19 in order to achieve a consistent combination between the two experiments. In the LHCb analysis, the background component, which was not included in the fit for the previous result but whose effect was accounted for as an additional systematic uncertainty, is now included in the standard fit. The following modifications are made to the CMS analysis: the branching fraction is updated to a more recent prediction63, 64 of ; the phase space model of the decay is changed to a more appropriate semi-leptonic decay model63; and the decay time bias correction for the , previously absent from the analysis, is now calculated and applied with a different correction for each category of the multivariate discriminant.

These modifications result in changes in the individual results of each experiment. The modified CMS analysis, applied on the CMS data, yields

while the LHCb results change to

These results are only slightly different from the published ones and are in agreement with each other.

Simultaneous fit

The goal of the analysis presented in this Letter is to combine the full data sets of the two experiments to reduce the uncertainties on the branching fractions of the signal decays obtained from the individual determinations. A simultaneous unbinned extended maximum likelihood fit is performed to the data of the two experiments, using the invariant-mass distributions of all 20 MVA discriminant categories of both experiments. The invariant-mass distributions are defined in the dimuon mass ranges [4.9, 5.9] GeV/c2 and [4.9, 6.0] GeV/c2 for the CMS and LHCb experiments, respectively. The branching fractions of the signal decays, the hadronization fraction ratio fd/fs, and the branching fraction of the normalization channel B+ right arrow J/ψK+ are treated as common parameters. The value of the B+ right arrow J/ψK+ branching fraction is the combination of results from five different experiments14, taking advantage of all their data to achieve the most precise input parameters for this analysis. The combined fit takes advantage of the larger data sample and proper treatment of the correlations between the individual measurements to increase the precision and reliability of the result, respectively.

Fit parameters, other than those of primary physics interest, whose limited knowledge affects the results, are called ‘nuisance parameters’. In particular, systematic uncertainties are modelled by introducing nuisance parameters into the statistical model and allowing them to vary in the fit; those for which additional knowledge is present are constrained using Gaussian distributions. The mean and standard deviation of these distributions are set to the central value and uncertainty obtained either from other measurements or from control channels. The statistical component of the final uncertainty on the branching fractions is obtained by repeating the fit after fixing all of the constrained nuisance parameters to their best fitted values. The systematic component is then calculated by subtracting in quadrature the statistical component from the total uncertainty. In addition to the free fit, a two-dimensional likelihood ratio scan in the plane (B0 right arrow µ+µ) versus is performed.

Feldman–Cousins confidence interval

The Feldman–Cousins likelihood ratio ordering procedure30 is a unified frequentist method to construct single- and double-sided confidence intervals for parameters of a given model adapted to the data. It provides a natural transition between single-sided confidence intervals, used to define upper or lower limits, and double-sided ones. Since the single-experiment results18, 19 showed that the B0 right arrow µ+µ signal is at the edge of the probability region customarily used to assert statistically significant evidence for a result, a Feldman–Cousins procedure is performed. This allows a more reliable determination of the confidence interval and significance of this signal without the assumptions required for the use of Wilks’ theorem. In addition, a prescription for the treatment of nuisance parameters has to be chosen because scanning the whole parameter space in the presence of more than a few parameters is computationally too intensive. In this case the procedure described by the ATLAS and CMS Higgs combination group65 is adopted. For each point of the space of the relevant parameters, the nuisance parameters are fixed to their best value estimated by the mean of a maximum likelihood fit to the data with the value of (B0 right arrow µ+µ) fixed and all nuisance parameters profiled with Gaussian penalties. Sampling distributions are constructed for each tested point of the parameter of interest by generating simulated experiments and performing maximum likelihood fits in which the Gaussian mean values of the external constraints on the nuisance parameters are randomized around the best-fit values for the nuisance parameters used to generate the simulated experiments. The sampling distribution is constructed from the distribution of the negative log-likelihood ratio evaluated on the simulated experiments by performing one likelihood fit in which the value of (B0 right arrow µ+µ) is free to float and another with the (B0 right arrow µ+µ) fixed to the tested point value. This sampling distribution is then converted to a confidence level by evaluating the fraction of simulated experiments entries with a value for the negative log-likelihood ratio greater than or equal to the value observed in the data for each tested point. The results of this procedure are shown in Extended Data Fig. 5.

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Acknowledgements

We express our gratitude to colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at CERN, at the CMS institutes and at the LHCb institutes. In addition, we gratefully acknowledge the computing centres and personnel of the Worldwide LHC Computing Grid for delivering so effectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC, the CMS and the LHCb detectors provided by CERN and by many funding agencies. The following agencies provide support for both CMS and LHCb: CAPES, CNPq, FAPERJ and FINEP (Brazil); NSFC (China); CNRS/IN2P3 (France); BMBF, DFG and HGF (Germany); SFI (Ireland); INFN (Italy); NASU (Ukraine); STFC (UK); and NSF (USA). Agencies that provide support for CMS only are BMWFW and FWF (Austria); FNRS and FWO (Belgium); FAPESP (Brazil); MES (Bulgaria); CAS and MoST (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); MoER, ERC IUT and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA (France); GSRT (Greece); OTKA and NIH (Hungary); DAE and DST (India); IPM (Iran); NRF and WCU (Republic of Korea); LAS (Lithuania); MOE and UM (Malaysia); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR (Russia); MESTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR and NSTDA (Thailand); TUBITAK and TAEK (Turkey); SFFR (Ukraine); and DOE (USA). Agencies that provide support for only LHCb are: FINEP (Brazil); MPG (Germany); FOM and NWO (The Netherlands); MNiSW and NCN (Poland); MEN/IFA (Romania); MinES and FANO (Russia); MinECo (Spain); SNSF and SER (Switzerland). Individuals from the CMS collaboration have received support from the Marie-Curie programme and the European Research Council and EPLANET (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture (FRIABelgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Council of Science and Industrial Research, India; the HOMING PLUS programme of Foundation for Polish Science, cofinanced from European Union, Regional Development Fund; the Compagnia di San Paolo (Torino); the Consorzio per la Fisica (Trieste); MIUR project 20108T4XTM (Italy); the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF; and the National Priorities Research Program by Qatar National Research Fund. Individual groups or members of the LHCb collaboration have received support from EPLANET, Marie Skłodowska-Curie Actions and ERC (European Union), Conseil général de Haute-Savoie, Labex ENIGMASS and OCEVU, Région Auvergne (France), RFBR (Russia), XuntaGal and GENCAT (Spain), Royal Society and Royal Commission for the Exhibition of 1851 (UK). LHCb is also thankful for the computing resources and the access to software R&D tools provided by Yandex LLC (Russia). The CMS and LHCb collaborations are indebted to the communities behind the multiple open source software packages on which they depend.

Author information

Affiliations

  1. Yerevan Physics Institute, Yerevan, Armenia.

    • V. Khachatryan,
    • A.M. Sirunyan &
    • A. Tumasyan
  2. Institut für Hochenergiephysik der OeAW, Wien, Austria.

    • W. Adam,
    • T. Bergauer,
    • M. Dragicevic,
    • J. Erö,
    • M. Friedl,
    • R. Frühwirth,
    • V.M. Ghete,
    • C. Hartl,
    • N. Hörmann,
    • J. Hrubec,
    • M. Jeitler,
    • W. Kiesenhofer,
    • V. Knünz,
    • M. Krammer,
    • I. Krätschmer,
    • D. Liko,
    • I. Mikulec,
    • D. Rabady,
    • B. Rahbaran,
    • H. Rohringer,
    • R. Schöfbeck,
    • J. Strauss,
    • W. Treberer-Treberspurg,
    • W. Waltenberger &
    • C.-E. Wulz
  3. National Centre for Particle and High Energy Physics, Minsk, Belarus.

    • V. Mossolov,
    • N. Shumeiko &
    • J. Suarez Gonzalez
  4. Universiteit Antwerpen, Antwerpen, Belgium.

    • S. Alderweireldt,
    • S. Bansal,
    • T. Cornelis,
    • E.A. De Wolf,
    • X. Janssen,
    • A. Knutsson,
    • J. Lauwers,
    • S. Luyckx,
    • S. Ochesanu,
    • R. Rougny,
    • M. Van De Klundert,
    • H. Van Haevermaet,
    • P. Van Mechelen,
    • N. Van Remortel &
    • A. Van Spilbeeck
  5. Vrije Universiteit Brussel, Brussel, Belgium.

    • F. Blekman,
    • S. Blyweert,
    • J. D'Hondt,
    • N. Daci,
    • N. Heracleous,
    • J. Keaveney,
    • S. Lowette,
    • M. Maes,
    • A. Olbrechts,
    • Q. Python,
    • D. Strom,
    • S. Tavernier,
    • W. Van Doninck,
    • P. Van Mulders,
    • G.P. Van Onsem &
    • I. Villella
  6. Université Libre de Bruxelles, Bruxelles, Belgium.

    • C. Caillol,
    • B. Clerbaux,
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    • D. Dobur,
    • L. Favart,
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    • A. Léonard,
    • A. Mohammadi,
    • L. Perniè,
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    • T. Reis,
    • T. Seva,
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  7. Ghent University, Ghent, Belgium.

    • V. Adler,
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    • L. Benucci,
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  8. Université Catholique de Louvain, Louvain-la-Neuve, Belgium.

    • S. Basegmez,
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    • G. Bruno,
    • R. Castello,
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  9. Université de Mons, Mons, Belgium.

    • N. Beliy,
    • T. Caebergs,
    • E. Daubie &
    • G.H. Hammad
  10. Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil.

    • W.L. Aldá Júnior,
    • G.A. Alves,
    • L. Brito,
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    • T. Dos Reis Martins,
    • C. Mora Herrera,
    • M.E. Pol &
    • P. Rebello Teles
  11. Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.

    • W. Carvalho,
    • J. Chinellato,
    • A. Custódio,
    • E.M. Da Costa,
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    • D. Matos Figueiredo,
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    • A. Santoro,
    • A. Sznajder,
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    • A. Vilela Pereira
  12. Universidade Estadual Paulista, Universidade Federal do ABC, São Paulo, Brazil.

  13. Universidade Estadual Paulista.

    • S. Dogra,
    • T.R. Fernandez Perez Tomei,
    • S.F. Novaes &
    • Sandra S. Padula
  14. Universidade Federal do ABC.

    • C.A. Bernardes,
    • E.M. Gregores &
    • P.G. Mercadante
  15. Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria.

    • A. Aleksandrov,
    • V. Genchev,
    • R. Hadjiiska,
    • P. Iaydjiev,
    • A. Marinov,
    • S. Piperov,
    • M. Rodozov,
    • G. Sultanov &
    • M. Vutova
  16. University of Sofia, Sofia, Bulgaria.

    • A. Dimitrov,
    • I. Glushkov,
    • L. Litov,
    • B. Pavlov &
    • P. Petkov
  17. Institute of High Energy Physics, Beijing, China.

    • J.G. Bian,
    • G.M. Chen,
    • H.S. Chen,
    • M. Chen,
    • T. Cheng,
    • R. Du,
    • C.H. Jiang,
    • R. Plestina,
    • F. Romeo,
    • J. Tao &
    • Z. Wang
  18. State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China.

    • C. Asawatangtrakuldee,
    • Y. Ban,
    • Q. Li,
    • S. Liu,
    • Y. Mao,
    • S.J. Qian,
    • D. Wang,
    • Z. Xu &
    • W. Zou
  19. Universidad de Los Andes, Bogota, Colombia.

    • C. Avila,
    • A. Cabrera,
    • L.F. Chaparro Sierra,
    • C. Florez,
    • J.P. Gomez,
    • B. Gomez Moreno &
    • J.C. Sanabria
  20. University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, Croatia.

    • N. Godinovic,
    • D. Lelas,
    • D. Polic &
    • I. Puljak
  21. University of Split, Faculty of Science, Split, Croatia.

    • Z. Antunovic &
    • M. Kovac
  22. Institute Rudjer Boskovic, Zagreb, Croatia.

    • V. Brigljevic,
    • K. Kadija,
    • J. Luetic,
    • D. Mekterovic &
    • L. Sudic
  23. University of Cyprus, Nicosia, Cyprus.

    • A. Attikis,
    • G. Mavromanolakis,
    • J. Mousa,
    • C. Nicolaou,
    • F. Ptochos &
    • P.A. Razis
  24. Charles University, Prague, Czech Republic.

    • M. Bodlak,
    • M. Finger &
    • M. Finger Jr.
  25. Academy of Scientific Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt.

    • Y. Assran,
    • A. Ellithi Kamel,
    • M.A. Mahmoud &
    • A. Radi
  26. National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.

    • M. Kadastik,
    • M. Murumaa,
    • M. Raidal &
    • A. Tiko
  27. Department of Physics, University of Helsinki, Helsinki, Finland.

    • P. Eerola,
    • G. Fedi &
    • M. Voutilainen
  28. Helsinki Institute of Physics, Helsinki, Finland.

    • J. Härkönen,
    • V. Karimäki,
    • R. Kinnunen,
    • M.J. Kortelainen,
    • T. Lampén,
    • K. Lassila-Perini,
    • S. Lehti,
    • T. Lindén,
    • P. Luukka,
    • T. Mäenpää,
    • T. Peltola,
    • E. Tuominen,
    • J. Tuominiemi,
    • E. Tuovinen &
    • L. Wendland
  29. Lappeenranta University of Technology, Lappeenranta, Finland.

    • J. Talvitie &
    • T. Tuuva
  30. DSM/IRFU, CEA/Saclay, Gif-sur-Yvette, France.

    • M. Besancon,
    • F. Couderc,
    • M. Dejardin,
    • D. Denegri,
    • B. Fabbro,
    • J.L. Faure,
    • C. Favaro,
    • F. Ferri,
    • S. Ganjour,
    • A. Givernaud,
    • P. Gras,
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    • P. Jarry,
    • E. Locci,
    • J. Malcles,
    • J. Rander,
    • A. Rosowsky &
    • M. Titov
  31. Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France.

    • S. Baffioni,
    • F. Beaudette,
    • P. Busson,
    • C. Charlot,
    • T. Dahms,
    • M. Dalchenko,
    • L. Dobrzynski,
    • N. Filipovic,
    • A. Florent,
    • R. Granier de Cassagnac,
    • L. Mastrolorenzo,
    • P. Miné,
    • C. Mironov,
    • I.N. Naranjo,
    • M. Nguyen,
    • C. Ochando,
    • G. Ortona,
    • P. Paganini,
    • S. Regnard,
    • R. Salerno,
    • J.B. Sauvan,
    • Y. Sirois,
    • C. Veelken,
    • Y. Yilmaz &
    • A. Zabi
  32. Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Université de Haute Alsace Mulhouse, CNRS/IN2P3, Strasbourg, France.

    • J.-L. Agram,
    • J. Andrea,
    • A. Aubin,
    • D. Bloch,
    • J.-M. Brom,
    • E.C. Chabert,
    • C. Collard,
    • E. Conte,
    • J.-C. Fontaine,
    • D. Gelé,
    • U. Goerlach,
    • C. Goetzmann,
    • A.-C. Le Bihan,
    • K. Skovpen &
    • P. Van Hove
  33. Centre de Calcul de l'Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France.

    • S. Gadrat
  34. Université de Lyon, Université Claude Bernard Lyon 1, CNRS-IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France.

    • S. Beauceron,
    • N. Beaupere,
    • G. Boudoul,
    • E. Bouvier,
    • S. Brochet,
    • C.A. Carrillo Montoya,
    • J. Chasserat,
    • R. Chierici,
    • D. Contardo,
    • P. Depasse,
    • H. El Mamouni,
    • J. Fan,
    • J. Fay,
    • S. Gascon,
    • M. Gouzevitch,
    • B. Ille,
    • T. Kurca,
    • M. Lethuillier,
    • L. Mirabito,
    • S. Perries,
    • J.D. Ruiz Alvarez,
    • D. Sabes,
    • L. Sgandurra,
    • V. Sordini,
    • M. Vander Donckt,
    • P. Verdier,
    • S. Viret &
    • H. Xiao
  35. Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi, Georgia.

    • Z. Tsamalaidze
  36. RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany.

    • C. Autermann,
    • S. Beranek,
    • M. Bontenackels,
    • M. Edelhoff,
    • L. Feld,
    • A. Heister,
    • O. Hindrichs,
    • K. Klein,
    • A. Ostapchuk,
    • F. Raupach,
    • J. Sammet,
    • S. Schael,
    • J.F. Schulte,
    • H. Weber,
    • B. Wittmer &
    • V. Zhukov
  37. RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany.

    • M. Ata,
    • M. Brodski,
    • E. Dietz-Laursonn,
    • D. Duchardt,
    • M. Erdmann,
    • R. Fischer,
    • A. Güth,
    • T. Hebbeker,
    • C. Heidemann,
    • K. Hoepfner,
    • D. Klingebiel,
    • S. Knutzen,
    • P. Kreuzer,
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    • P. Papacz,
    • H. Reithler,
    • S.A. Schmitz,
    • L. Sonnenschein,
    • D. Teyssier,
    • S. Thüer &
    • M. Weber
  38. RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany.

    • V. Cherepanov,
    • Y. Erdogan,
    • G. Flügge,
    • H. Geenen,
    • M. Geisler,
    • W. Haj Ahmad,
    • F. Hoehle,
    • B. Kargoll,
    • T. Kress,
    • Y. Kuessel,
    • A. Künsken,
    • J. Lingemann,
    • A. Nowack,
    • I.M. Nugent,
    • O. Pooth &
    • A. Stahl
  39. Deutsches Elektronen-Synchrotron, Hamburg, Germany.

    • M. Aldaya Martin,
    • I. Asin,
    • N. Bartosik,
    • J. Behr,
    • U. Behrens,
    • A.J. Bell,
    • A. Bethani,
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    • E. Ron,
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    • J. Salfeld-Nebgen,
    • P. Saxena,
    • T. Schoerner-Sadenius,
    • M. Schröder,
    • C. Seitz,
    • S. Spannagel,
    • A.D.R. Vargas Trevino,
    • R. Walsh &
    • C. Wissing
  40. University of Hamburg, Hamburg, Germany.

    • V. Blobel,
    • M. Centis Vignali,
    • A.R. Draeger,
    • J. Erfle,
    • E. Garutti,
    • K. Goebel,
    • M. Görner,
    • J. Haller,
    • M. Hoffmann,
    • R.S. Höing,
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    • H. Kirschenmann,
    • R. Klanner,
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    • J. Lange,
    • T. Lapsien,
    • T. Lenz,
    • I. Marchesini,
    • J. Ott,
    • T. Peiffer,
    • A. Perieanu,
    • N. Pietsch,
    • J. Poehlsen,
    • T. Poehlsen,
    • D. Rathjens,
    • C. Sander,
    • H. Schettler,
    • P. Schleper,
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    • A. Schmidt,
    • M. Seidel,
    • V. Sola,
    • H. Stadie,
    • G. Steinbrück,
    • D. Troendle,
    • E. Usai,
    • L. Vanelderen &
    • A. Vanhoefer
  41. Institut für Experimentelle Kernphysik, Karlsruhe, Germany.

    • C. Barth,
    • C. Baus,
    • J. Berger,
    • C. Böser,
    • E. Butz,
    • T. Chwalek,
    • W. De Boer,
    • A. Descroix,
    • A. Dierlamm,
    • M. Feindt,
    • F. Frensch,
    • M. Giffels,
    • A. Gilbert,
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    • T. Hauth,
    • U. Husemann,
    • I. Katkov,
    • A. Kornmayer,
    • E. Kuznetsova,
    • P. Lobelle Pardo,
    • M.U. Mozer,
    • T. Müller,
    • Th. Müller,
    • A. Nürnberg,
    • G. Quast,
    • K. Rabbertz,
    • S. Röcker,
    • H.J. Simonis,
    • F.M. Stober,
    • R. Ulrich,
    • J. Wagner-Kuhr,
    • S. Wayand,
    • T. Weiler &
    • R. Wolf
  42. Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece.

    • G. Anagnostou,
    • G. Daskalakis,
    • T. Geralis,
    • V.A. Giakoumopoulou,
    • A. Kyriakis,
    • D. Loukas,
    • A. Markou,
    • C. Markou,
    • A. Psallidas &
    • I. Topsis-Giotis
  43. University of Athens, Athens, Greece.

    • A. Agapitos,
    • S. Kesisoglou,
    • A. Panagiotou,
    • N. Saoulidou &
    • E. Stiliaris
  44. University of Ioánnina, Ioánnina, Greece.

    • X. Aslanoglou,
    • I. Evangelou,
    • G. Flouris,
    • C. Foudas,
    • P. Kokkas,
    • N. Manthos,
    • I. Papadopoulos,
    • E. Paradas &
    • J. Strologas
  45. Wigner Research Centre for Physics, Budapest, Hungary.

    • G. Bencze,
    • C. Hajdu,
    • P. Hidas,
    • D. Horvath,
    • F. Sikler,
    • V. Veszpremi,
    • G. Vesztergombi &
    • A.J. Zsigmond
  46. Institute of Nuclear Research ATOMKI, Debrecen, Hungary.

    • N. Beni,
    • S. Czellar,
    • J. Karancsi,
    • J. Molnar,
    • J. Palinkas &
    • Z. Szillasi
  47. University of Debrecen, Debrecen, Hungary.

    • A. Makovec,
    • P. Raics,
    • Z.L. Trocsanyi &
    • B. Ujvari
  48. National Institute of Science Education and Research, Bhubaneswar, India.

    • N. Sahoo &
    • S.K. Swain
  49. Panjab University, Chandigarh, India.

    • S.B. Beri,
    • V. Bhatnagar,
    • R. Gupta,
    • U. Bhawandeep,
    • A.K. Kalsi,
    • M. Kaur,
    • R. Kumar,
    • M. Mittal,
    • N. Nishu &
    • J.B. Singh
  50. University of Delhi, Delhi, India.

    • Ashok Kumar,
    • Arun Kumar,
    • S. Ahuja,
    • A. Bhardwaj,
    • B.C. Choudhary,
    • A. Kumar,
    • S. Malhotra,
    • M. Naimuddin,
    • K. Ranjan &
    • V. Sharma
  51. Saha Institute of Nuclear Physics, Kolkata, India.

    • S. Banerjee,
    • S. Bhattacharya,
    • K. Chatterjee,
    • S. Dutta,
    • B. Gomber,
    • Sa. Jain,
    • Sh. Jain,
    • R. Khurana,
    • A. Modak,
    • S. Mukherjee,
    • D. Roy,
    • S. Sarkar &
    • M. Sharan
  52. Bhabha Atomic Research Centre, Mumbai, India.

    • A. Abdulsalam,
    • D. Dutta,
    • S. Kailas,
    • V. Kumar,
    • A.K. Mohanty,
    • L.M. Pant,
    • P. Shukla &
    • A. Topkar
  53. Tata Institute of Fundamental Research, Mumbai, India.

    • T. Aziz,
    • S. Banerjee,
    • S. Bhowmik,
    • R.M. Chatterjee,
    • R.K. Dewanjee,
    • S. Dugad,
    • S. Ganguly,
    • S. Ghosh,
    • M. Guchait,
    • A. Gurtu,
    • G. Kole,
    • S. Kumar,
    • M. Maity,
    • G. Majumder,
    • K. Mazumdar,
    • G.B. Mohanty,
    • B. Parida,
    • K. Sudhakar &
    • N. Wickramage
  54. Institute for Research in Fundamental Sciences (IPM), Tehran, Iran.

    • H. Bakhshiansohi,
    • H. Behnamian,
    • S.M. Etesami,
    • A. Fahim,
    • R. Goldouzian,
    • M. Khakzad,
    • M. Mohammadi Najafabadi,
    • M. Naseri,
    • S. Paktinat Mehdiabadi,
    • F. Rezaei Hosseinabadi,
    • B. Safarzadeh &
    • M. Zeinali
  55. University College Dublin, Dublin, Ireland.

    • M. Felcini &
    • M. Grunewald
  56. INFN Sezione di Bari, Università di Bari, Politecnico di Bari, Bari, Italy.

  57. INFN Sezione di Bari.

    • M. Abbrescia,
    • C. Calabria,
    • S.S. Chhibra,
    • A. Colaleo,
    • D. Creanza,
    • N. De Filippis,
    • M. De Palma,
    • L. Fiore,
    • G. Iaselli,
    • G. Maggi,
    • M. Maggi,
    • S. My,
    • S. Nuzzo,
    • A. Pompili,
    • G. Pugliese,
    • R. Radogna,
    • G. Selvaggi,
    • A. Sharma,
    • L. Silvestris,
    • R. Venditti &
    • P. Verwilligen
  58. Università di Bari.

    • M. Abbrescia,
    • C. Calabria,
    • S.S. Chhibra,
    • M. De Palma,
    • S. Nuzzo,
    • A. Pompili,
    • R. Radogna,
    • G. Selvaggi &
    • R. Venditti
  59. Politecnico di Bari.

    • D. Creanza,
    • N. De Filippis,
    • G. Iaselli,
    • G. Maggi,
    • S. My &
    • G. Pugliese
  60. INFN Sezione di Bologna, Università di Bologna, Bologna, Italy.

  61. INFN Sezione di Bologna.

    • G. Abbiendi,
    • A.C. Benvenuti,
    • D. Bonacorsi,
    • S. Braibant-Giacomelli,
    • L. Brigliadori,
    • R. Campanini,
    • P. Capiluppi,
    • A. Castro,
    • F.R. Cavallo,
    • G. Codispoti,
    • M. Cuffiani,
    • G.M. Dallavalle,
    • F. Fabbri,
    • A. Fanfani,
    • D. Fasanella,
    • P. Giacomelli,
    • C. Grandi,
    • L. Guiducci,
    • S. Marcellini,
    • G. Masetti,
    • A. Montanari,
    • F.L. Navarria,
    • A. Perrotta,
    • F. Primavera,
    • A.M. Rossi,
    • T. Rovelli,
    • G.P. Siroli,
    • N. Tosi &
    • R. Travaglini
  62. Università di Bologna.

    • D. Bonacorsi,
    • S. Braibant-Giacomelli,
    • L. Brigliadori,
    • R. Campanini,
    • P. Capiluppi,
    • A. Castro,
    • G. Codispoti,
    • M. Cuffiani,
    • A. Fanfani,
    • D. Fasanella,
    • L. Guiducci,
    • F.L. Navarria,
    • F. Primavera,
    • A.M. Rossi,
    • T. Rovelli,
    • G.P. Siroli,
    • N. Tosi &
    • R. Travaglini
  63. INFN Sezione di Catania, Università di Catania, CSFNSM, Catania, Italy.

  64. INFN Sezione di Catania.

    • S. Albergo,
    • G. Cappello,
    • M. Chiorboli,
    • S. Costa,
    • F. Giordano,
    • R. Potenza,
    • A. Tricomi &
    • C. Tuve
  65. Università di Catania.

    • S. Albergo,
    • M. Chiorboli,
    • S. Costa,
    • R. Potenza,
    • A. Tricomi &
    • C. Tuve
  66. CSFNSM.

  67. INFN Sezione di Firenze, Università di Firenze, Firenze, Italy.

  68. INFN Sezione di Firenze.

    • G. Barbagli,
    • V. Ciulli,
    • C. Civinini,
    • R. D'Alessandro,
    • E. Focardi,
    • E. Gallo,
    • S. Gonzi,
    • V. Gori,
    • P. Lenzi,
    • M. Meschini,
    • S. Paoletti,
    • G. Sguazzoni &
    • A. Tropiano
  69. Università di Firenze.

    • V. Ciulli,
    • R. D'Alessandro,
    • E. Focardi,
    • S. Gonzi,
    • V. Gori,
    • P. Lenzi &
    • A. Tropiano
  70. INFN Laboratori Nazionali di Frascati, Frascati, Italy.

    • L. Benussi,
    • S. Bianco,
    • F. Fabbri &
    • D. Piccolo
  71. INFN Sezione di Genova, Università di Genova, Genova, Italy.

  72. INFN Sezione di Genova.

    • R. Ferretti,
    • F. Ferro,
    • M. Lo Vetere,
    • E. Robutti &
    • S. Tosi
  73. Università di Genova.

    • R. Ferretti,
    • M. Lo Vetere &
    • S. Tosi
  74. INFN Sezione di Milano-Bicocca, Università di Milano-Bicocca, Milano, Italy.

  75. INFN Sezione di Milano-Bicocca.

    • M.E. Dinardo,
    • S. Fiorendi,
    • S. Gennai,
    • R. Gerosa,
    • A. Ghezzi,
    • P. Govoni,
    • M.T. Lucchini,
    • S. Malvezzi,
    • R.A. Manzoni,
    • A. Martelli,
    • B. Marzocchi,
    • D. Menasce,
    • L. Moroni,
    • M. Paganoni,
    • D. Pedrini,
    • S. Ragazzi,
    • N. Redaelli &
    • T. Tabarelli de Fatis
  76. Università di Milano-Bicocca.

    • M.E. Dinardo,
    • S. Fiorendi,
    • R. Gerosa,
    • A. Ghezzi,
    • P. Govoni,
    • M.T. Lucchini,
    • R.A. Manzoni,
    • A. Martelli,
    • B. Marzocchi,
    • M. Paganoni,
    • S. Ragazzi &
    • T. Tabarelli de Fatis
  77. INFN Sezione di Napoli, Università di Napoli 'Federico II', Università della Basilicata (Potenza), Università G. Marconi (Roma), Napoli, Italy.

  78. INFN Sezione di Napoli.

    • S. Buontempo,
    • N. Cavallo,
    • S. Di Guida,
    • F. Fabozzi,
    • A.O.M. Iorio,
    • L. Lista,
    • S. Meola,
    • M. Merola &
    • P. Paolucci
  79. Università di Napoli 'Federico II'.

    • A.O.M. Iorio
  80. Università della Basilicata (Potenza).

    • N. Cavallo &
    • F. Fabozzi
  81. Università G. Marconi (Roma).

    • S. Di Guida &
    • S. Meola
  82. INFN Sezione di Padova, Università di Padova, Università di Trento (Trento), Padova, Italy.

  83. INFN Sezione di Padova.

    • P. Azzi,
    • N. Bacchetta,
    • D. Bisello,
    • A. Branca,
    • R. Carlin,
    • P. Checchia,
    • M. Dall'Osso,
    • T. Dorigo,
    • U. Dosselli,
    • M. Galanti,
    • F. Gasparini,
    • U. Gasparini,
    • P. Giubilato,
    • A. Gozzelino,
    • K. Kanishchev,
    • S. Lacaprara,
    • M. Margoni,
    • A.T. Meneguzzo,
    • J. Pazzini,
    • N. Pozzobon,
    • P. Ronchese,
    • F. Simonetto,
    • E. Torassa,
    • M. Tosi,
    • P. Zotto,
    • A. Zucchetta &
    • G. Zumerle
  84. Università di Padova.

    • D. Bisello,
    • A. Branca,
    • R. Carlin,
    • M. Dall'Osso,
    • M. Galanti,
    • F. Gasparini,
    • U. Gasparini,
    • P. Giubilato,
    • M. Margoni,
    • A.T. Meneguzzo,
    • J. Pazzini,
    • N. Pozzobon,
    • P. Ronchese,
    • F. Simonetto,
    • M. Tosi,
    • P. Zotto,
    • A. Zucchetta &
    • G. Zumerle
  85. Università di Trento (Trento).

    • K. Kanishchev
  86. INFN Sezione di Pavia, Università di Pavia, Pavia, Italy.

  87. INFN Sezione di Pavia.

    • M. Gabusi,
    • S.P. Ratti,
    • V. Re,
    • C. Riccardi,
    • P. Salvini &
    • P. Vitulo
  88. Università di Pavia.

    • M. Gabusi,
    • S.P. Ratti,
    • C. Riccardi &
    • P. Vitulo
  89. INFN Sezione di Perugia, Università di Perugia, Perugia, Italy.

  90. INFN Sezione di Perugia.

    • M. Biasini,
    • G.M. Bilei,
    • D. Ciangottini,
    • L. Fanò,
    • P. Lariccia,
    • G. Mantovani,
    • M. Menichelli,
    • A. Saha,
    • A. Santocchia &
    • A. Spiezia
  91. Università di Perugia.

    • M. Biasini,
    • D. Ciangottini,
    • L. Fanò,
    • P. Lariccia,
    • G. Mantovani,
    • A. Santocchia &
    • A. Spiezia
  92. INFN Sezione di Pisa, Università di Pisa, Scuola Normale Superiore di Pisa, Pisa, Italy.

  93. INFN Sezione di Pisa.

    • K. Androsov,
    • P. Azzurri,
    • G. Bagliesi,
    • J. Bernardini,
    • T. Boccali,
    • G. Broccolo,
    • R. Castaldi,
    • M.A. Ciocci,
    • R. Dell'Orso,
    • S. Donato,
    • F. Fiori,
    • L. Foà,
    • A. Giassi,
    • M.T. Grippo,
    • F. Ligabue,
    • T. Lomtadze,
    • L. Martini,
    • A. Messineo,
    • C.S. Moon,
    • F. Palla,
    • A. Rizzi,
    • A. Savoy-Navarro,
    • A.T. Serban,
    • P. Spagnolo,
    • P. Squillacioti,
    • R. Tenchini,
    • G. Tonelli,
    • A. Venturi,
    • P.G. Verdini &
    • C. Vernieri
  94. Università di Pisa.

    • L. Martini,
    • A. Messineo,
    • A. Rizzi &
    • G. Tonelli
  95. Scuola Normale Superiore di Pisa.

    • G. Broccolo,
    • S. Donato,
    • F. Fiori,
    • L. Foà,
    • F. Ligabue &
    • C. Vernieri
  96. INFN Sezione di Roma, Università di Roma, Roma, Italy.

  97. INFN Sezione di Roma.

    • L. Barone,
    • F. Cavallari,
    • G. D'imperio,
    • D. Del Re,
    • M. Diemoz,
    • C. Jorda,
    • E. Longo,
    • F. Margaroli,
    • P. Meridiani,
    • F. Micheli,
    • S. Nourbakhsh,
    • G. Organtini,
    • R. Paramatti,
    • S. Rahatlou,
    • C. Rovelli,
    • F. Santanastasio,
    • L. Soffi &
    • P. Traczyk
  98. Università di Roma.

    • L. Barone,
    • G. D'imperio,
    • D. Del Re,
    • E. Longo,
    • F. Margaroli,
    • F. Micheli,
    • S. Nourbakhsh,
    • G. Organtini,
    • S. Rahatlou,
    • F. Santanastasio,
    • L. Soffi &
    • P. Traczyk
  99. INFN Sezione di Torino, Università di Torino, Università del Piemonte Orientale (Novara), Torino, Italy.

  100. INFN Sezione di Torino.

    • N. Amapane,
    • R. Arcidiacono,
    • S. Argiro,
    • M. Arneodo,
    • R. Bellan,
    • C. Biino,
    • N. Cartiglia,
    • S. Casasso,
    • M. Costa,
    • A. Degano,
    • N. Demaria,
    • L. Finco,
    • C. Mariotti,
    • S. Maselli,
    • E. Migliore,
    • V. Monaco,
    • M. Musich,
    • M.M. Obertino,
    • L. Pacher,
    • N. Pastrone,
    • M. Pelliccioni,
    • G.L. Pinna Angioni,
    • A. Potenza,
    • A. Romero,
    • M. Ruspa,
    • R. Sacchi,
    • A. Solano,
    • A. Staiano &
    • U. Tamponi
  101. Università di Torino.

    • N. Amapane,
    • S. Argiro,
    • R. Bellan,
    • S. Casasso,
    • M. Costa,
    • A. Degano,
    • L. Finco,
    • E. Migliore,
    • V. Monaco,
    • L. Pacher,
    • G.L. Pinna Angioni,
    • A. Potenza,
    • A. Romero,
    • R. Sacchi &
    • A. Solano
  102. Università del Piemonte Orientale (Novara).

    • R. Arcidiacono,
    • M. Arneodo,
    • M.M. Obertino &
    • M. Ruspa
  103. INFN Sezione di Trieste, Università di Trieste, Trieste, Italy.

  104. INFN Sezione di Trieste.

    • S. Belforte,
    • V. Candelise,
    • M. Casarsa,
    • F. Cossutti,
    • G. Della Ricca,
    • B. Gobbo,
    • C. La Licata,
    • M. Marone,
    • A. Schizzi,
    • T. Umer &
    • A. Zanetti
  105. Università di Trieste.

    • V. Candelise,
    • G. Della Ricca,
    • C. La Licata,
    • M. Marone,
    • A. Schizzi &
    • T. Umer
  106. Kangwon National University, Chunchon, Korea.

    • S. Chang,
    • A. Kropivnitskaya &
    • S.K. Nam
  107. Kyungpook National University, Daegu, Korea.

    • D.H. Kim,
    • G.N. Kim,
    • M.S. Kim,
    • D.J. Kong,
    • S. Lee,
    • Y.D. Oh,
    • H. Park,
    • A. Sakharov &
    • D.C. Son
  108. Chonbuk National University, Jeonju, Korea.

    • T.J. Kim
  109. Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea.

    • J.Y. Kim &
    • S. Song
  110. Korea University, Seoul, Korea.

    • S. Choi,
    • D. Gyun,
    • B. Hong,
    • M. Jo,
    • H. Kim,
    • Y. Kim,
    • B. Lee,
    • K.S. Lee,
    • S.K. Park &
    • Y. Roh
  111. Seoul National University, Seoul, Korea.

    • H.D. Yoo
  112. University of Seoul, Seoul, Korea.

    • M. Choi,
    • J.H. Kim,
    • I.C. Park,
    • G. Ryu &
    • M.S. Ryu
  113. Sungkyunkwan University, Suwon, Korea.

    • Y. Choi,
    • Y.K. Choi,
    • J. Goh,
    • D. Kim,
    • E. Kwon,
    • J. Lee &
    • I. Yu
  114. Vilnius University, Vilnius, Lithuania.

    • A. Juodagalvis
  115. National Centre for Particle Physics, Universiti Malaya, Kuala Lumpur, Malaysia.

    • J.R. Komaragiri &
    • M.A.B. Md Ali
  116. Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico.

    • E. Casimiro Linares,
    • H. Castilla-Valdez,
    • E. De La Cruz-Burelo,
    • I. Heredia-de La Cruz,
    • A. Hernandez-Almada,
    • R. Lopez-Fernandez &
    • A. Sanchez-Hernandez
  117. Universidad Iberoamericana, Mexico City, Mexico.

    • S. Carrillo Moreno &
    • F. Vazquez Valencia
  118. Benemerita Universidad Autonoma de Puebla, Puebla, Mexico.

    • I. Pedraza &
    • H.A. Salazar Ibarguen
  119. Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico.

    • A. Morelos Pineda
  120. University of Auckland, Auckland, New Zealand.

    • D. Krofcheck
  121. University of Canterbury, Christchurch, New Zealand.

    • P.H. Butler &
    • S. Reucroft
  122. National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan.

    • A. Ahmad,
    • M. Ahmad,
    • Q. Hassan,
    • H.R. Hoorani,
    • W.A. Khan,
    • T. Khurshid &
    • M. Shoaib
  123. National Centre for Nuclear Research, Swierk, Poland.

    • H. Bialkowska,
    • M. Bluj,
    • B. Boimska,
    • T. Frueboes,
    • M. Górski,
    • M. Kazana,
    • K. Nawrocki,
    • K. Romanowska-Rybinska,
    • M. Szleper &
    • P. Zalewski
  124. Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland.

    • G. Brona,
    • K. Bunkowski,
    • M. Cwiok,
    • W. Dominik,
    • K. Doroba,
    • A. Kalinowski,
    • M. Konecki,
    • J. Krolikowski,
    • M. Misiura,
    • M. Olszewski &
    • W. Wolszczak
  125. Laboratório de Instrumentação e Física Experimental de Partículas, Lisboa, Portugal.

    • P. Bargassa,
    • C. Beirão Da Cruz E Silva,
    • P. Faccioli,
    • P.G. Ferreira Parracho,
    • M. Gallinaro,
    • L. Lloret Iglesias,
    • F. Nguyen,
    • J. Rodrigues Antunes,
    • J. Seixas,
    • J. Varela &
    • P. Vischia
  126. Joint Institute for Nuclear Research, Dubna, Russia.

    • S. Afanasiev,
    • P. Bunin,
    • M. Gavrilenko,
    • I. Golutvin,
    • I. Gorbunov,
    • A. Kamenev,
    • V. Karjavin,
    • V. Konoplyanikov,
    • A. Lanev,
    • A. Malakhov,
    • V. Matveev,
    • P. Moisenz,
    • V. Palichik,
    • V. Perelygin,
    • S. Shmatov,
    • N. Skatchkov,
    • V. Smirnov &
    • A. Zarubin
  127. Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia.

    • V. Golovtsov,
    • Y. Ivanov,
    • V. Kim,
    • P. Levchenko,
    • V. Murzin,
    • V. Oreshkin,
    • I. Smirnov,
    • V. Sulimov,
    • L. Uvarov,
    • S. Vavilov,
    • A. Vorobyev &
    • An. Vorobyev
  128. Institute for Nuclear Research, Moscow, Russia.

    • Yu. Andreev,
    • A. Dermenev,
    • S. Gninenko,
    • N. Golubev,
    • M. Kirsanov,
    • N. Krasnikov,
    • A. Pashenkov,
    • D. Tlisov &
    • A. Toropin
  129. Institute for Theoretical and Experimental Physics, Moscow, Russia.

    • V. Epshteyn,
    • V. Gavrilov,
    • N. Lychkovskaya,
    • V. Popov,
    • I. Pozdnyakov,
    • G. Safronov,
    • S. Semenov,
    • A. Spiridonov,
    • V. Stolin,
    • E. Vlasov &
    • A. Zhokin
  130. P.N. Lebedev Physical Institute, Moscow, Russia.

    • V. Andreev,
    • M. Azarkin,
    • I. Dremin,
    • M. Kirakosyan,
    • A. Leonidov,
    • G. Mesyats,
    • S.V. Rusakov &
    • A. Vinogradov
  131. Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia.

    • A. Belyaev,
    • E. Boos,
    • M. Dubinin,
    • L. Dudko,
    • A. Ershov,
    • A. Gribushin,
    • V. Klyukhin,
    • O. Kodolova,
    • I. Lokhtin,
    • S. Obraztsov,
    • S. Petrushanko,
    • V. Savrin &
    • A. Snigirev
  132. State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia.

    • I. Azhgirey,
    • I. Bayshev,
    • S. Bitioukov,
    • V. Kachanov,
    • A. Kalinin,
    • D. Konstantinov,
    • V. Krychkine,
    • V. Petrov,
    • R. Ryutin,
    • A. Sobol,
    • L. Tourtchanovitch,
    • S. Troshin,
    • N. Tyurin,
    • A. Uzunian &
    • A. Volkov
  133. University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia.

    • P. Adzic,
    • M. Ekmedzic,
    • J. Milosevic &
    • V. Rekovic
  134. Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain.

    • J. Alcaraz Maestre,
    • C. Battilana,
    • E. Calvo,
    • M. Cerrada,
    • M. Chamizo Llatas,
    • N. Colino,
    • B. De La Cruz,
    • A. Delgado Peris,
    • D. Domínguez Vázquez,
    • A. Escalante Del Valle,
    • C. Fernandez Bedoya,
    • J.P. Fernández Ramos,
    • J. Flix,
    • M.C. Fouz,
    • P. Garcia-Abia,
    • O. Gonzalez Lopez,
    • S. Goy Lopez,
    • J.M. Hernandez,
    • M.I. Josa,
    • E. Navarro De Martino,
    • A. Pérez-Calero Yzquierdo,
    • J. Puerta Pelayo,
    • A. Quintario Olmeda,
    • I. Redondo,
    • L. Romero &
    • M.S. Soares
  135. Universidad Autónoma de Madrid, Madrid, Spain.

    • C. Albajar,
    • J.F. de Trocóniz,
    • M. Missiroli &
    • D. Moran
  136. Universidad de Oviedo, Oviedo, Spain.

    • H. Brun,
    • J. Cuevas,
    • J. Fernandez Menendez,
    • S. Folgueras &
    • I. Gonzalez Caballero
  137. Instituto de Física de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain.

    • J.A. Brochero Cifuentes,
    • I.J. Cabrillo,
    • A. Calderon,
    • J. Duarte Campderros,
    • M. Fernandez,
    • G. Gomez,
    • A. Graziano,
    • A. Lopez Virto,
    • J. Marco,
    • R. Marco,
    • C. Martinez Rivero,
    • F. Matorras,
    • F.J. Munoz Sanchez,
    • J. Piedra Gomez,
    • T. Rodrigo,
    • A.Y. Rodríguez-Marrero,
    • A. Ruiz-Jimeno,
    • L. Scodellaro,
    • I. Vila &
    • R. Vilar Cortabitarte
  138. CERN, European Organization for Nuclear Research, Geneva, Switzerland.

    • D. Abbaneo,
    • E. Auffray,
    • G. Auzinger,
    • M. Bachtis,
    • P. Baillon,
    • A.H. Ball,
    • D. Barney,
    • A. Benaglia,
    • J. Bendavid,
    • L. Benhabib,
    • J.F. Benitez,
    • C. Bernet,
    • P. Bloch,
    • A. Bocci,
    • A. Bonato,
    • O. Bondu,
    • C. Botta,
    • H. Breuker,
    • T. Camporesi,
    • G. Cerminara,
    • S. Colafranceschi,
    • M. D'Alfonso,
    • D. d'Enterria,
    • A. Dabrowski,
    • A. David,
    • F. De Guio,
    • A. De Roeck,
    • S. De Visscher,
    • E. Di Marco,
    • M. Dobson,
    • M. Dordevic,
    • N. Dupont-Sagorin,
    • A. Elliott-Peisert,
    • G. Franzoni,
    • W. Funk,
    • D. Gigi,
    • K. Gill,
    • D. Giordano,
    • M. Girone,
    • F. Glege,
    • R. Guida,
    • S. Gundacker,
    • M. Guthoff,
    • J. Hammer,
    • M. Hansen,
    • P. Harris,
    • J. Hegeman,
    • V. Innocente,
    • P. Janot,
    • K. Kousouris,
    • K. Krajczar,
    • P. Lecoq,
    • C. Lourenço,
    • N. Magini,
    • L. Malgeri,
    • M. Mannelli,
    • J. Marrouche,
    • L. Masetti,
    • F. Meijers,
    • S. Mersi,
    • E. Meschi,
    • F. Moortgat,
    • S. Morovic,
    • M. Mulders,
    • L. Orsini,
    • L. Pape,
    • E. Perez,
    • L. Perrozzi,
    • A. Petrilli,
    • G. Petrucciani,
    • A. Pfeiffer,
    • M. Pimiä,
    • D. Piparo,
    • M. Plagge,
    • A. Racz,
    • G. Rolandi,
    • M. Rovere,
    • H. Sakulin,
    • C. Schäfer,
    • C. Schwick,
    • A. Sharma,
    • P. Siegrist,
    • P. Silva,
    • M. Simon,
    • P. Sphicas,
    • D. Spiga,
    • J. Steggemann,
    • B. Stieger,
    • M. Stoye,
    • Y. Takahashi,
    • D. Treille,
    • A. Tsirou,
    • G.I. Veres,
    • N. Wardle,
    • H.K. Wöhri,
    • H. Wollny &
    • W.D. Zeuner
  139. Paul Scherrer Institut, Villigen, Switzerland.

    • W. Bertl,
    • K. Deiters,
    • W. Erdmann,
    • R. Horisberger,
    • Q. Ingram,
    • H.C. Kaestli,
    • D. Kotlinski,
    • D. Renker &
    • T. Rohe
  140. Institute for Particle Physics, ETH Zurich, Zurich, Switzerland.

    • F. Bachmair,
    • L. Bäni,
    • L. Bianchini,
    • M.A. Buchmann,
    • B. Casal,
    • N. Chanon,
    • G. Dissertori,
    • M. Dittmar,
    • M. Donegà,
    • M. Dünser,
    • P. Eller,
    • C. Grab,
    • D. Hits,
    • J. Hoss,
    • W. Lustermann,
    • B. Mangano,
    • A.C. Marini,
    • M. Marionneau,
    • P. Martinez Ruiz del Arbol,
    • M. Masciovecchio,
    • D. Meister,
    • N. Mohr,
    • P. Musella,
    • C. Nägeli,
    • F. Nessi-Tedaldi,
    • F. Pandolfi,
    • F. Pauss,
    • M. Peruzzi,
    • M. Quittnat,
    • L. Rebane,
    • M. Rossini,
    • A. Starodumov,
    • M. Takahashi,
    • K. Theofilatos,
    • R. Wallny &
    • H.A. Weber
  141. Universität Zürich, Zurich, Switzerland.

    • C. Amsler,
    • M.F. Canelli,
    • V. Chiochia,
    • A. De Cosa,
    • A. Hinzmann,
    • T. Hreus,
    • B. Kilminster,
    • C. Lange,
    • B. Millan Mejias,
    • J. Ngadiuba,
    • D. Pinna,
    • P. Robmann,
    • F.J. Ronga,
    • S. Taroni,
    • M. Verzetti &
    • Y. Yang
  142. National Central University, Chung-Li, Taiwan.

    • M. Cardaci,
    • K.H. Chen,
    • C. Ferro,
    • C.M. Kuo,
    • W. Lin,
    • Y.J. Lu,
    • R. Volpe &
    • S.S. Yu
  143. National Taiwan University (NTU), Taipei, Taiwan.

    • P. Chang,
    • Y.H. Chang,
    • Y.W. Chang,
    • Y. Chao,
    • K.F. Chen,
    • P.H. Chen,
    • C. Dietz,
    • U. Grundler,
    • W.-S. Hou,
    • K.Y. Kao,
    • Y.F. Liu,
    • R.-S. Lu,
    • D. Majumder,
    • E. Petrakou,
    • Y.M. Tzeng &
    • R. Wilken
  144. Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok, Thailand.

    • B. Asavapibhop,
    • G. Singh,
    • N. Srimanobhas &
    • N. Suwonjandee
  145. Cukurova University, Adana, Turkey.

    • A. Adiguzel,
    • M.N. Bakirci,
    • S. Cerci,
    • C. Dozen,
    • I. Dumanoglu,
    • E. Eskut,
    • S. Girgis,
    • G. Gokbulut,
    • E. Gurpinar,
    • I. Hos,
    • E.E. Kangal,
    • A. Kayis Topaksu,
    • G. Onengut,
    • K. Ozdemir,
    • S. Ozturk,
    • A. Polatoz,
    • D. Sunar Cerci,
    • B. Tali,
    • H. Topakli &
    • M. Vergili
  146. Middle East Technical University, Physics Department, Ankara, Turkey.

    • I.V. Akin,
    • B. Bilin,
    • S. Bilmis,
    • H. Gamsizkan,
    • B. Isildak,
    • G. Karapinar,
    • K. Ocalan,
    • S. Sekmen,
    • U.E. Surat,
    • M. Yalvac &
    • M. Zeyrek
  147. Bogazici University, Istanbul, Turkey.

    • E.A. Albayrak,
    • E. Gülmez,
    • M. Kaya,
    • O. Kaya &
    • T. Yetkin
  148. Istanbul Technical University, Istanbul, Turkey.

    • K. Cankocak &
    • F.I. Vardarlı
  149. National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine.

    • L. Levchuk &
    • P. Sorokin
  150. University of Bristol, Bristol, United Kingdom.

    • J.J. Brooke,
    • E. Clement,
    • D. Cussans,
    • H. Flacher,
    • J. Goldstein,
    • M. Grimes,
    • G.P. Heath,
    • H.F. Heath,
    • J. Jacob,
    • L. Kreczko,
    • C. Lucas,
    • Z. Meng,
    • D.M. Newbold,
    • S. Paramesvaran,
    • A. Poll,
    • T. Sakuma,
    • S. Senkin &
    • V.J. Smith
  151. Rutherford Appleton Laboratory, Didcot, United Kingdom.

    • K.W. Bell,
    • A. Belyaev,
    • C. Brew,
    • R.M. Brown,
    • D.J.A. Cockerill,
    • J.A. Coughlan,
    • K. Harder,
    • S. Harper,
    • E. Olaiya,
    • D. Petyt,
    • C.H. Shepherd-Themistocleous,
    • A. Thea,
    • I.R. Tomalin,
    • T. Williams,
    • W.J. Womersley &
    • S.D. Worm
  152. Imperial College, London, United Kingdom.

    • M. Baber,
    • R. Bainbridge,
    • O. Buchmuller,
    • D. Burton,
    • D. Colling,
    • N. Cripps,
    • P. Dauncey,
    • G. Davies,
    • M. Della Negra,
    • P. Dunne,
    • W. Ferguson,
    • J. Fulcher,
    • D. Futyan,
    • G. Hall,
    • G. Iles,
    • M. Jarvis,
    • G. Karapostoli,
    • M. Kenzie,
    • R. Lane,
    • R. Lucas,
    • L. Lyons,
    • A.-M. Magnan,
    • S. Malik,
    • B. Mathias,
    • J. Nash,
    • A. Nikitenko,
    • J. Pela,
    • M. Pesaresi,
    • K. Petridis,
    • D.M. Raymond,
    • S. Rogerson,
    • A. Rose,
    • C. Seez,
    • P. Sharp,
    • A. Tapper,
    • M. Vazquez Acosta,
    • T. Virdee &
    • S.C. Zenz
  153. Brunel University, Uxbridge, United Kingdom.

    • J.E. Cole,
    • P.R. Hobson,
    • A. Khan,
    • P. Kyberd,
    • D. Leggat,
    • D. Leslie,
    • I.D. Reid,
    • P. Symonds,
    • L. Teodorescu &
    • M. Turner
  154. Baylor University, Waco, USA.

    • J. Dittmann,
    • K. Hatakeyama,
    • A. Kasmi,
    • H. Liu &
    • T. Scarborough
  155. The University of Alabama, Tuscaloosa, USA.

    • O. Charaf,
    • S.I. Cooper,
    • C. Henderson &
    • P. Rumerio
  156. Boston University, Boston, USA.

    • A. Avetisyan,
    • T. Bose,
    • C. Fantasia,
    • P. Lawson,
    • C. Richardson,
    • J. Rohlf,
    • J. St. John &
    • L. Sulak
  157. Brown University, Providence, USA.

    • J. Alimena,
    • E. Berry,
    • S. Bhattacharya,
    • G. Christopher,
    • D. Cutts,
    • Z. Demiragli,
    • N. Dhingra,
    • A. Ferapontov,
    • A. Garabedian,
    • U. Heintz,
    • G. Kukartsev,
    • E. Laird,
    • G. Landsberg,
    • M. Luk,
    • M. Narain,
    • M. Segala,
    • T. Sinthuprasith,
    • T. Speer &
    • J. Swanson
  158. University of California, Davis, Davis, USA.

    • R. Breedon,
    • G. Breto,
    • M. Calderon De La Barca Sanchez,
    • S. Chauhan,
    • M. Chertok,
    • J. Conway,
    • R. Conway,
    • P.T. Cox,
    • R. Erbacher,
    • M. Gardner,
    • W. Ko,
    • R. Lander,
    • M. Mulhearn,
    • D. Pellett,
    • J. Pilot,
    • F. Ricci-Tam,
    • S. Shalhout,
    • J. Smith,
    • M. Squires,
    • D. Stolp,
    • M. Tripathi,
    • S. Wilbur &
    • R. Yohay
  159. University of California, Los Angeles, USA.

    • R. Cousins,
    • P. Everaerts,
    • C. Farrell,
    • J. Hauser,
    • M. Ignatenko,
    • G. Rakness,
    • E. Takasugi,
    • V. Valuev &
    • M. Weber
  160. University of California, Riverside, Riverside, USA.

    • K. Burt,
    • R. Clare,
    • J. Ellison,
    • J.W. Gary,
    • G. Hanson,
    • J. Heilman,
    • M. Ivova Rikova,
    • P. Jandir,
    • E. Kennedy,
    • F. Lacroix,
    • O.R. Long,
    • A. Luthra,
    • M. Malberti,
    • M. Olmedo Negrete,
    • A. Shrinivas,
    • S. Sumowidagdo &
    • S. Wimpenny
  161. University of California, San Diego, La Jolla, USA.

    • J.G. Branson,
    • G.B. Cerati,
    • S. Cittolin,
    • R.T. D'Agnolo,
    • A. Holzner,
    • R. Kelley,
    • D. Klein,
    • D. Kovalskyi,
    • J. Letts,
    • I. Macneill,
    • D. Olivito,
    • S. Padhi,
    • C. Palmer,
    • M. Pieri,
    • M. Sani,
    • V. Sharma,
    • S. Simon,
    • Y. Tu,
    • A. Vartak,
    • C. Welke,
    • F. Würthwein &
    • A. Yagil
  162. University of California, Santa Barbara, Santa Barbara, USA.

    • D. Barge,
    • J. Bradmiller-Feld,
    • C. Campagnari,
    • T. Danielson,
    • A. Dishaw,
    • V. Dutta,
    • K. Flowers,
    • M. Franco Sevilla,
    • P. Geffert,
    • C. George,
    • F. Golf,
    • L. Gouskos,
    • J. Incandela,
    • C. Justus,
    • N. Mccoll,
    • J. Richman,
    • D. Stuart,
    • W. To,
    • C. West &
    • J. Yoo
  163. California Institute of Technology, Pasadena, USA.

    • A. Apresyan,
    • A. Bornheim,
    • J. Bunn,
    • Y. Chen,
    • J. Duarte,
    • A. Mott,
    • H.B. Newman,
    • C. Pena,
    • M. Pierini,
    • M. Spiropulu,
    • J.R. Vlimant,
    • R. Wilkinson,
    • S. Xie &
    • R.Y. Zhu
  164. Carnegie Mellon University, Pittsburgh, USA.

    • V. Azzolini,
    • A. Calamba,
    • B. Carlson,
    • T. Ferguson,
    • Y. Iiyama,
    • M. Paulini,
    • J. Russ,
    • H. Vogel &
    • I. Vorobiev
  165. University of Colorado at Boulder, Boulder, USA.

    • J.P. Cumalat,
    • W.T. Ford,
    • A. Gaz,
    • M. Krohn,
    • E. Luiggi Lopez,
    • U. Nauenberg,
    • J.G. Smith,
    • K. Stenson &
    • S.R. Wagner
  166. Cornell University, Ithaca, USA.

    • J. Alexander,
    • A. Chatterjee,
    • J. Chaves,
    • J. Chu,
    • S. Dittmer,
    • N. Eggert,
    • N. Mirman,
    • G. Nicolas Kaufman,
    • J.R. Patterson,
    • A. Ryd,
    • E. Salvati,
    • L. Skinnari,
    • W. Sun,
    • W.D. Teo,
    • J. Thom,
    • J. Thompson,
    • J. Tucker,
    • Y. Weng,
    • L. Winstrom &
    • P. Wittich
  167. Fairfield University, Fairfield, USA.

    • D. Winn
  168. Fermi National Accelerator Laboratory, Batavia, USA.

    • S. Abdullin,
    • M. Albrow,
    • J. Anderson,
    • G. Apollinari,
    • L.A.T. Bauerdick,
    • A. Beretvas,
    • J. Berryhill,
    • P.C. Bhat,
    • G. Bolla,
    • K. Burkett,
    • J.N. Butler,
    • H.W.K. Cheung,
    • F. Chlebana,
    • S. Cihangir,
    • V.D. Elvira,
    • I. Fisk,
    • J. Freeman,
    • Y. Gao,
    • E. Gottschalk,
    • L. Gray,
    • D. Green,
    • S. Grünendahl,
    • O. Gutsche,
    • J. Hanlon,
    • D. Hare,
    • R.M. Harris,
    • J. Hirschauer,
    • B. Hooberman,
    • S. Jindariani,
    • M. Johnson,
    • U. Joshi,
    • K. Kaadze,
    • B. Klima,
    • B. Kreis,
    • S. Kwan,
    • J. Linacre,
    • D. Lincoln,
    • R. Lipton,
    • T. Liu,
    • J. Lykken,
    • K. Maeshima,
    • J.M. Marraffino,
    • V.I. Martinez Outschoorn,
    • S. Maruyama,
    • D. Mason,
    • P. McBride,
    • P. Merkel,
    • K. Mishra,
    • S. Mrenna,
    • S. Nahn,
    • C. Newman-Holmes,
    • V. O'Dell,
    • O. Prokofyev,
    • E. Sexton-Kennedy,
    • S. Sharma,
    • A. Soha,
    • W.J. Spalding,
    • L. Spiegel,
    • L. Taylor,
    • S. Tkaczyk,
    • N.V. Tran,
    • L. Uplegger,
    • E.W. Vaandering,
    • R. Vidal,
    • A. Whitbeck,
    • J. Whitmore &
    • F. Yang
  169. University of Florida, Gainesville, USA.

    • D. Acosta,
    • P. Avery,
    • P. Bortignon,
    • D. Bourilkov,
    • M. Carver,
    • D. Curry,
    • S. Das,
    • M. De Gruttola,
    • G.P. Di Giovanni,
    • R.D. Field,
    • M. Fisher,
    • I.K. Furic,
    • J. Hugon,
    • J. Konigsberg,
    • A. Korytov,
    • T. Kypreos,
    • J.F. Low,
    • K. Matchev,
    • H. Mei,
    • P. Milenovic,
    • G. Mitselmakher,
    • L. Muniz,
    • A. Rinkevicius,
    • L. Shchutska,
    • M. Snowball,
    • D. Sperka,
    • J. Yelton &
    • M. Zakaria
  170. Florida International University, Miami, USA.

    • S. Hewamanage,
    • S. Linn,
    • P. Markowitz,
    • G. Martinez &
    • J.L. Rodriguez
  171. Florida State University, Tallahassee, USA.

    • T. Adams,
    • A. Askew,
    • J. Bochenek,
    • B. Diamond,
    • J. Haas,
    • S. Hagopian,
    • V. Hagopian,
    • K.F. Johnson,
    • H. Prosper,
    • V. Veeraraghavan &
    • M. Weinberg
  172. Florida Institute of Technology, Melbourne, USA.

    • M.M. Baarmand,
    • M. Hohlmann,
    • H. Kalakhety &
    • F. Yumiceva
  173. University of Illinois at Chicago (UIC), Chicago, USA.

    • M.R. Adams,
    • L. Apanasevich,
    • D. Berry,
    • R.R. Betts,
    • I. Bucinskaite,
    • R. Cavanaugh,
    • O. Evdokimov,
    • L. Gauthier,
    • C.E. Gerber,
    • D.J. Hofman,
    • P. Kurt,
    • D.H. Moon,
    • C. O'Brien,
    • I.D. Sandoval Gonzalez,
    • C. Silkworth,
    • P. Turner &
    • N. Varelas
  174. The University of Iowa, Iowa City, USA.

    • B. Bilki,
    • W. Clarida,
    • K. Dilsiz,
    • M. Haytmyradov,
    • J.-P. Merlo,
    • H. Mermerkaya,
    • A. Mestvirishvili,
    • A. Moeller,
    • J. Nachtman,
    • H. Ogul,
    • Y. Onel,
    • F. Ozok,
    • A. Penzo,
    • R. Rahmat,
    • S. Sen,
    • P. Tan,
    • E. Tiras,
    • J. Wetzel &
    • K. Yi
  175. Johns Hopkins University, Baltimore, USA.

    • B.A. Barnett,
    • B. Blumenfeld,
    • S. Bolognesi,
    • D. Fehling,
    • A.V. Gritsan,
    • P. Maksimovic,
    • C. Martin &
    • M. Swartz
  176. The University of Kansas, Lawrence, USA.

    • P. Baringer,
    • A. Bean,
    • G. Benelli,
    • C. Bruner,
    • R.P. Kenny III,
    • M. Malek,
    • M. Murray,
    • D. Noonan,
    • S. Sanders,
    • J. Sekaric,
    • R. Stringer,
    • Q. Wang &
    • J.S. Wood
  177. Kansas State University, Manhattan, USA.

    • I. Chakaberia,
    • A. Ivanov,
    • S. Khalil,
    • M. Makouski,
    • Y. Maravin,
    • L.K. Saini,
    • N. Skhirtladze &
    • I. Svintradze
  178. Lawrence Livermore National Laboratory, Livermore, USA.

    • J. Gronberg,
    • D. Lange,
    • F. Rebassoo &
    • D. Wright
  179. University of Maryland, College Park, USA.

    • A. Baden,
    • A. Belloni,
    • B. Calvert,
    • S.C. Eno,
    • J.A. Gomez,
    • N.J. Hadley,
    • R.G. Kellogg,
    • T. Kolberg,
    • Y. Lu,
    • A.C. Mignerey,
    • K. Pedro,
    • A. Skuja,
    • M.B. Tonjes &
    • S.C. Tonwar
  180. Massachusetts Institute of Technology, Cambridge, USA.

    • A. Apyan,
    • R. Barbieri,
    • G. Bauer,
    • W. Busza,
    • I.A. Cali,
    • M. Chan,
    • L. Di Matteo,
    • G. Gomez Ceballos,
    • M. Goncharov,
    • D. Gulhan,
    • M. Klute,
    • Y.S. Lai,
    • Y.-J. Lee,
    • A. Levin,
    • P.D. Luckey,
    • T. Ma,
    • C. Paus,
    • D. Ralph,
    • C. Roland,
    • G. Roland,
    • G.S.F. Stephans,
    • K. Sumorok,
    • D. Velicanu,
    • J. Veverka,
    • B. Wyslouch,
    • M. Yang,
    • M. Zanetti &
    • V. Zhukova
  181. University of Minnesota, Minneapolis, USA.

    • B. Dahmes,
    • A. Gude,
    • S.C. Kao,
    • K. Klapoetke,
    • Y. Kubota,
    • J. Mans,
    • N. Pastika,
    • R. Rusack,
    • A. Singovsky,
    • N. Tambe &
    • J. Turkewitz
  182. University of Mississippi, Oxford, USA.

    • J.G. Acosta &
    • S. Oliveros
  183. University of Nebraska-Lincoln, Lincoln, USA.

    • E. Avdeeva,
    • K. Bloom,
    • S. Bose,
    • D.R. Claes,
    • A. Dominguez,
    • R. Gonzalez Suarez,
    • J. Keller,
    • D. Knowlton,
    • I. Kravchenko,
    • J. Lazo-Flores,
    • F. Meier,
    • F. Ratnikov,
    • G.R. Snow &
    • M. Zvada
  184. State University of New York at Buffalo, Buffalo, USA.

    • J. Dolen,
    • A. Godshalk,
    • I. Iashvili,
    • A. Kharchilava,
    • A. Kumar &
    • S. Rappoccio
  185. Northeastern University, Boston, USA.

    • G. Alverson,
    • E. Barberis,
    • D. Baumgartel,
    • M. Chasco,
    • A. Massironi,
    • D.M. Morse,
    • D. Nash,
    • T. Orimoto,
    • D. Trocino,
    • R.-J. Wang,
    • D. Wood &
    • J. Zhang
  186. Northwestern University, Evanston, USA.

    • K.A. Hahn,
    • A. Kubik,
    • N. Mucia,
    • N. Odell,
    • B. Pollack,
    • A. Pozdnyakov,
    • M. Schmitt,
    • S. Stoynev,
    • K. Sung,
    • M. Velasco &
    • S. Won
  187. University of Notre Dame, Notre Dame, USA.

    • A. Brinkerhoff,
    • K.M. Chan,
    • A. Drozdetskiy,
    • M. Hildreth,
    • C. Jessop,
    • D.J. Karmgard,
    • N. Kellams,
    • K. Lannon,
    • S. Lynch,
    • N. Marinelli,
    • Y. Musienko,
    • T. Pearson,
    • M. Planer,
    • R. Ruchti,
    • G. Smith,
    • N. Valls,
    • M. Wayne,
    • M. Wolf &
    • A. Woodard
  188. The Ohio State University, Columbus, USA.

    • L. Antonelli,
    • J. Brinson,
    • B. Bylsma,
    • L.S. Durkin,
    • S. Flowers,
    • A. Hart,
    • C. Hill,
    • R. Hughes,
    • K. Kotov,
    • T.Y. Ling,
    • W. Luo,
    • D. Puigh,
    • M. Rodenburg,
    • B.L. Winer,
    • H. Wolfe &
    • H.W. Wulsin
  189. Princeton University, Princeton, USA.

    • O. Driga,
    • P. Elmer,
    • J. Hardenbrook,
    • P. Hebda,
    • A. Hunt,
    • S.A. Koay,
    • P. Lujan,
    • D. Marlow,
    • T. Medvedeva,
    • M. Mooney,
    • J. Olsen,
    • P. Piroué,
    • X. Quan,
    • H. Saka,
    • D. Stickland,
    • C. Tully,
    • J.S. Werner &
    • A. Zuranski
  190. University of Puerto Rico, Mayaguez, USA.

    • E. Brownson,
    • S. Malik,
    • H. Mendez &
    • J.E. Ramirez Vargas
  191. Purdue University, West Lafayette, USA.

    • V.E. Barnes,
    • D. Benedetti,
    • D. Bortoletto,
    • M. De Mattia,
    • L. Gutay,
    • Z. Hu,
    • M.K. Jha,
    • M. Jones,
    • K. Jung,
    • M. Kress,
    • N. Leonardo,
    • D.H. Miller,
    • N. Neumeister,
    • B.C. Radburn-Smith,
    • X. Shi,
    • I. Shipsey,
    • D. Silvers,
    • A. Svyatkovskiy,
    • F. Wang,
    • W. Xie,
    • L. Xu &
    • J. Zablocki
  192. Purdue University Calumet, Hammond, USA.

    • N. Parashar &
    • J. Stupak
  193. Rice University, Houston, USA.

    • A. Adair,
    • B. Akgun,
    • K.M. Ecklund,
    • F.J.M. Geurts,
    • W. Li,
    • B. Michlin,
    • B.P. Padley,
    • R. Redjimi,
    • J. Roberts &
    • J. Zabel
  194. University of Rochester, Rochester, USA.

    • B. Betchart,
    • A. Bodek,
    • R. Covarelli,
    • P. de Barbaro,
    • R. Demina,
    • Y. Eshaq,
    • T. Ferbel,
    • A. Garcia-Bellido,
    • P. Goldenzweig,
    • J. Han,
    • A. Harel,
    • A. Khukhunaishvili,
    • S. Korjenevski,
    • G. Petrillo &
    • D. Vishnevskiy
  195. The Rockefeller University, New York, USA.

    • R. Ciesielski,
    • L. Demortier,
    • K. Goulianos &
    • C. Mesropian
  196. Rutgers, The State University of New Jersey, Piscataway, USA.

    • S. Arora,
    • A. Barker,
    • J.P. Chou,
    • C. Contreras-Campana,
    • E. Contreras-Campana,
    • D. Duggan,
    • D. Ferencek,
    • Y. Gershtein,
    • R. Gray,
    • E. Halkiadakis,
    • D. Hidas,
    • S. Kaplan,
    • A. Lath,
    • S. Panwalkar,
    • M. Park,
    • R. Patel,
    • S. Salur,
    • S. Schnetzer,
    • S. Somalwar,
    • R. Stone,
    • S. Thomas,
    • P. Thomassen &
    • M. Walker
  197. University of Tennessee, Knoxville, USA.

    • K. Rose,
    • S. Spanier &
    • A. York
  198. Texas A&M University, College Station, USA.

    • O. Bouhali,
    • A. Castaneda Hernandez,
    • R. Eusebi,
    • W. Flanagan,
    • J. Gilmore,
    • T. Kamon,
    • V. Khotilovich,
    • V. Krutelyov,
    • R. Montalvo,
    • I. Osipenkov,
    • Y. Pakhotin,
    • A. Perloff,
    • J. Roe,
    • A. Rose,
    • A. Safonov,
    • I. Suarez,
    • A. Tatarinov &
    • K.A. Ulmer
  199. Texas Tech University, Lubbock, USA.

    • N. Akchurin,
    • C. Cowden,
    • J. Damgov,
    • C. Dragoiu,
    • P.R. Dudero,
    • J. Faulkner,
    • K. Kovitanggoon,
    • S. Kunori,
    • S.W. Lee,
    • T. Libeiro &
    • I. Volobouev
  200. Vanderbilt University, Nashville, USA.

    • E. Appelt,
    • A.G. Delannoy,
    • S. Greene,
    • A. Gurrola,
    • W. Johns,
    • C. Maguire,
    • Y. Mao,
    • A. Melo,
    • M. Sharma,
    • P. Sheldon,
    • B. Snook,
    • S. Tuo &
    • J. Velkovska
  201. University of Virginia, Charlottesville, USA.

    • M.W. Arenton,
    • S. Boutle,
    • B. Cox,
    • B. Francis,
    • J. Goodell,
    • R. Hirosky,
    • A. Ledovskoy,
    • H. Li,
    • C. Lin,
    • C. Neu &
    • J. Wood
  202. Wayne State University, Detroit, USA.

    • C. Clarke,
    • R. Harr,
    • P.E. Karchin,
    • C. Kottachchi Kankanamge Don,
    • P. Lamichhane &
    • J. Sturdy
  203. University of Wisconsin, Madison, USA.

    • D.A. Belknap,
    • D. Carlsmith,
    • M. Cepeda,
    • S. Dasu,
    • L. Dodd,
    • S. Duric,
    • E. Friis,
    • R. Hall-Wilton,
    • M. Herndon,
    • A. Hervé,
    • P. Klabbers,
    • A. Lanaro,
    • C. Lazaridis,
    • A. Levine,
    • R. Loveless,
    • A. Mohapatra,
    • I. Ojalvo,
    • T. Perry,
    • G.A. Pierro,
    • G. Polese,
    • I. Ross,
    • T. Sarangi,
    • A. Savin,
    • W.H. Smith,
    • D. Taylor,
    • C. Vuosalo &
    • N. Woods
  204. Vienna University of Technology, Vienna, Austria.

    • R. Frühwirth,
    • M. Jeitler,
    • M. Krammer &
    • C.-E. Wulz
  205. CERN, European Organization for Nuclear Research, Geneva, Switzerland.

    • D. Rabady,
    • L. Perniè,
    • V. Genchev,
    • G. Boudoul,
    • D. Contardo,
    • J. Lingemann,
    • F. Hartmann,
    • A. Kornmayer,
    • A.K. Mohanty,
    • R. Radogna,
    • L. Silvestris,
    • F. Giordano,
    • S. Gennai,
    • R. Gerosa,
    • M.T. Lucchini,
    • B. Marzocchi,
    • S. Di Guida,
    • S. Meola,
    • P. Paolucci,
    • D. Ciangottini,
    • A. Spiezia,
    • S. Donato,
    • F. Palla,
    • F. Micheli,
    • P. Traczyk,
    • S. Casasso,
    • L. Finco,
    • V. Candelise &
    • D. Stickland
  206. Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Université de Haute Alsace Mulhouse, CNRS/IN2P3, Strasbourg, France.

    • C. Beluffi
  207. National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.

    • A. Giammanco
  208. Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia.

    • A. Popov,
    • V. Zhukov &
    • I. Katkov
  209. Universidade Estadual de Campinas, Campinas, Brazil.

    • J. Chinellato &
    • E.J. Tonelli Manganote
  210. Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France.

    • R. Plestina &
    • C. Bernet
  211. Joint Institute for Nuclear Research, Dubna, Russia.

    • M. Finger Jr. &
    • Z. Tsamalaidze
  212. Suez University, Suez, Egypt.

    • Y. Assran
  213. Cairo University, Cairo, Egypt.

    • A. Ellithi Kamel
  214. Fayoum University, El-Fayoum, Egypt.

    • M.A. Mahmoud
  215. Ain Shams University, Cairo, Egypt.

    • A. Radi
  216. Now at Sultan Qaboos University, Muscat, Oman.

    • A. Radi
  217. Université de Haute Alsace, Mulhouse, France.

    • J.-L. Agram,
    • E. Conte &
    • J.-C. Fontaine
  218. Brandenburg University of Technology, Cottbus, Germany.

    • M. Hempel,
    • W. Lohmann &
    • I. Marfin
  219. Institute of Nuclear Research ATOMKI, Debrecen, Hungary.

    • D. Horvath
  220. Eötvös Loránd University, Budapest, Hungary.

    • G. Vesztergombi &
    • G.I. Veres
  221. University of Debrecen, Debrecen, Hungary.

    • J. Karancsi
  222. University of Visva-Bharati, Santiniketan, India.

    • S. Bhowmik &
    • M. Maity
  223. Now at King Abdulaziz University, Jeddah, Saudi Arabia.

    • A. Gurtu
  224. University of Ruhuna, Matara, Sri Lanka.

    • N. Wickramage
  225. Isfahan University of Technology, Isfahan, Iran.

    • S.M. Etesami
  226. University of Tehran, Department of Engineering Science, Tehran, Iran.

    • A. Fahim
  227. Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran.

    • B. Safarzadeh
  228. Università degli Studi di Siena, Siena, Italy.

    • K. Androsov,
    • M.A. Ciocci,
    • M.T. Grippo &
    • P. Squillacioti
  229. Centre National de la Recherche Scientifique (CNRS) - IN2P3, Paris, France.

    • C.S. Moon
  230. Purdue University, West Lafayette, USA.

    • A. Savoy-Navarro
  231. Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Mexico.

    • I. Heredia-de La Cruz
  232. Institute for Nuclear Research, Moscow, Russia.

    • V. Matveev &
    • Y. Musienko
  233. St. Petersburg State Polytechnical University, St. Petersburg, Russia.

    • V. Kim
  234. California Institute of Technology, Pasadena, USA.

    • M. Dubinin
  235. Faculty of Physics, University of Belgrade, Belgrade, Serbia.

    • P. Adzic
  236. Facoltà Ingegneria, Università di Roma, Roma, Italy.

    • S. Colafranceschi
  237. Scuola Normale e Sezione dell'INFN, Pisa, Italy.

    • G. Rolandi
  238. University of Athens, Athens, Greece.

    • P. Sphicas
  239. Paul Scherrer Institut, Villigen, Switzerland.

    • C. Nägeli
  240. Institute for Theoretical and Experimental Physics, Moscow, Russia.

    • A. Starodumov &
    • A. Nikitenko
  241. Albert Einstein Center for Fundamental Physics, Bern, Switzerland.

    • C. Amsler
  242. Gaziosmanpasa University, Tokat, Turkey.

    • M.N. Bakirci,
    • S. Ozturk &
    • H. Topakli
  243. Adiyaman University, Adiyaman, Turkey.

    • S. Cerci,
    • D. Sunar Cerci &
    • B. Tali
  244. Cag University, Mersin, Turkey.

    • G. Onengut
  245. Anadolu University, Eskisehir, Turkey.

    • H. Gamsizkan
  246. Ozyegin University, Istanbul, Turkey.

    • B. Isildak
  247. Izmir Institute of Technology, Izmir, Turkey.

    • G. Karapinar
  248. Necmettin Erbakan University, Konya, Turkey.

    • K. Ocalan
  249. Mimar Sinan University, Istanbul, Istanbul, Turkey.

    • E.A. Albayrak &
    • F. Ozok
  250. Marmara University, Istanbul, Turkey.

    • M. Kaya
  251. Kafkas University, Kars, Turkey.

    • O. Kaya
  252. Yildiz Technical University, Istanbul, Turkey.

    • T. Yetkin
  253. Rutherford Appleton Laboratory, Didcot, United Kingdom.

    • D.M. Newbold &
    • R. Lucas
  254. School of Physics and Astronomy, University of Southampton, Southampton, United Kingdom.

    • A. Belyaev
  255. University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia.

    • P. Milenovic
  256. Argonne National Laboratory, Argonne, USA.

    • B. Bilki
  257. Erzincan University, Erzincan, Turkey.

    • H. Mermerkaya
  258. Texas A&M University at Qatar, Doha, Qatar.

    • O. Bouhali
  259. Kyungpook National University, Daegu, Korea.

    • T. Kamon
  260. Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil.

    • I. Bediaga,
    • J.M. De Miranda,
    • F. Ferreira Rodrigues,
    • A. Gomes,
    • A. Massafferri,
    • A.C. dos Reis &
    • A.B. Rodrigues
  261. Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.

    • S. Amato,
    • K. Carvalho Akiba,
    • L. De Paula,
    • O. Francisco,
    • M. Gandelman,
    • A. Hicheur,
    • J.H. Lopes,
    • D. Martins Tostes,
    • I. Nasteva,
    • J.M. Otalora Goicochea,
    • E. Polycarpo,
    • C. Potterat,
    • M.S. Rangel,
    • V. Salustino Guimaraes,
    • B. Souza De Paula &
    • D. Vieira
  262. Center for High Energy Physics, Tsinghua University, Beijing, China.

    • L. An,
    • Y. Gao,
    • F. Jing,
    • Y. Li,
    • Z. Yang,
    • X. Yuan,
    • Y. Zhang &
    • L. Zhong
  263. LAPP, Université de Savoie, CNRS/IN2P3, Annecy-Le-Vieux, France.

    • L. Beaucourt,
    • M. Chefdeville,
    • D. Decamp,
    • N. Déléage,
    • Ph. Ghez,
    • J.-P. Lees,
    • J.F. Marchand,
    • M.-N. Minard,
    • B. Pietrzyk,
    • W. Qian,
    • S. T'Jampens,
    • V. Tisserand &
    • E. Tournefier
  264. Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France.

    • Z. Ajaltouni,
    • M. Baalouch,
    • E. Cogneras,
    • O. Deschamps,
    • I. El Rifai,
    • M. Grabalosa Gándara,
    • P. Henrard,
    • M. Hoballah,
    • R. Lefèvre,
    • J. Maratas,
    • S. Monteil,
    • V. Niess &
    • P. Perret
  265. CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille, France.

    • C. Adrover,
    • S. Akar,
    • E. Aslanides,
    • J. Cogan,
    • W. Kanso,
    • R. Le Gac,
    • O. Leroy,
    • G. Mancinelli,
    • A. Mordà,
    • M. Perrin-Terrin,
    • J. Serrano &
    • A. Tsaregorodtsev
  266. LAL, Université Paris-Sud, CNRS/IN2P3, Orsay, France.

    • Y. Amhis,
    • S. Barsuk,
    • M. Borsato,
    • O. Kochebina,
    • J. Lefrançois,
    • F. Machefert,
    • A. Martín Sánchez,
    • M. Nicol,
    • P. Robbe,
    • M.-H. Schune,
    • M. Teklishyn,
    • A. Vallier,
    • B. Viaud &
    • G. Wormser
  267. LPNHE, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris, France.

    • E. Ben-Haim,
    • M. Charles,
    • S. Coquereau,
    • P. David,
    • L. Del Buono,
    • L. Henry &
    • F. Polci
  268. Fakultät Physik, Technische Universität Dortmund, Dortmund, Germany.

    • J. Albrecht,
    • T. Brambach,
    • Ch. Cauet,
    • M. Deckenhoff,
    • U. Eitschberger,
    • R. Ekelhof,
    • L. Gavardi,
    • F. Kruse,
    • F. Meier,
    • R. Niet,
    • C.J. Parkinson,
    • M. Schlupp,
    • A. Shires,
    • B. Spaan,
    • S. Swientek &
    • J. Wishahi
  269. Max-Planck-Institut für Kernphysik (MPIK), Heidelberg, Germany.

    • O. Aquines Gutierrez,
    • J. Blouw,
    • M. Britsch,
    • M. Fontana,
    • D. Popov,
    • M. Schmelling,
    • D. Volyanskyy &
    • M. Zavertyaev
  270. Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany.

    • S. Bachmann,
    • A. Bien,
    • A. Comerma-Montells,
    • M. De Cian,
    • F. Dordei,
    • S. Esen,
    • C. Färber,
    • E. Gersabeck,
    • L. Grillo,
    • X. Han,
    • S. Hansmann-Menzemer,
    • A. Jaeger,
    • M. Kolpin,
    • K. Kreplin,
    • G. Krocker,
    • B. Leverington,
    • J. Marks,
    • M. Meissner,
    • M. Neuner,
    • T. Nikodem,
    • P. Seyfert,
    • M. Stahl,
    • S. Stahl,
    • U. Uwer,
    • M. Vesterinen,
    • S. Wandernoth,
    • D. Wiedner &
    • A. Zhelezov
  271. School of Physics, University College Dublin, Dublin, Ireland.

    • R. McNulty,
    • R. Wallace &
    • W.C. Zhang
  272. Sezione INFN di Bari, Bari, Italy.

    • A. Palano
  273. Sezione INFN di Bologna, Bologna, Italy.

    • A. Carbone,
    • A. Falabella,
    • D. Galli,
    • U. Marconi,
    • N. Moggi,
    • M. Mussini,
    • S. Perazzini,
    • V. Vagnoni,
    • G. Valenti &
    • M. Zangoli
  274. Sezione INFN di Cagliari, Cagliari, Italy.

    • W. Bonivento,
    • S. Cadeddu,
    • A. Cardini,
    • V. Cogoni,
    • A. Contu,
    • A. Lai,
    • B. Liu,
    • G. Manca,
    • R. Oldeman,
    • B. Saitta &
    • C. Vacca
  275. Sezione INFN di Ferrara, Ferrara, Italy.

    • M. Andreotti,
    • W. Baldini,
    • C. Bozzi,
    • R. Calabrese,
    • M. Corvo,
    • M. Fiore,
    • M. Fiorini,
    • E. Luppi,
    • L.L. Pappalardo,
    • I. Shapoval,
    • G. Tellarini,
    • L. Tomassetti &
    • S. Vecchi
  276. Sezione INFN di Firenze, Firenze, Italy.

    • L. Anderlini,
    • A. Bizzeti,
    • M. Frosini,
    • G. Graziani,
    • G. Passaleva &
    • M. Veltri
  277. Laboratori Nazionali dell'INFN di Frascati, Frascati, Italy.

    • G. Bencivenni,
    • P. Campana,
    • P. De Simone,
    • G. Lanfranchi,
    • M. Palutan,
    • M. Rama,
    • A. Sarti,
    • B. Sciascia &
    • R. Vazquez Gomez
  278. Sezione INFN di Genova, Genova, Italy.

    • R. Cardinale,
    • F. Fontanelli,
    • S. Gambetta,
    • C. Patrignani,
    • A. Petrolini &
    • A. Pistone
  279. Sezione INFN di Milano Bicocca, Milano, Italy.

    • M. Calvi,
    • L. Cassina,
    • C. Gotti,
    • B. Khanji,
    • M. Kucharczyk &
    • C. Matteuzzi
  280. Sezione INFN di Milano, Milano, Italy.

    • J. Fu,
    • A. Geraci,
    • N. Neri &
    • F. Palombo
  281. Sezione INFN di Padova, Padova, Italy.

    • S. Amerio,
    • G. Collazuol,
    • S. Gallorini,
    • A. Gianelle,
    • D. Lucchesi,
    • A. Lupato,
    • M. Morandin,
    • M. Rotondo,
    • L. Sestini,
    • G. Simi &
    • R. Stroili
  282. Sezione INFN di Pisa, Pisa, Italy.

    • F. Bedeschi,
    • R. Cenci,
    • S. Leo,
    • P. Marino,
    • M.J. Morello,
    • G. Punzi,
    • S. Stracka &
    • J. Walsh
  283. Sezione INFN di Roma Tor Vergata, Roma, Italy.

    • G. Carboni,
    • E. Furfaro,
    • E. Santovetti &
    • A. Satta
  284. Sezione INFN di Roma La Sapienza, Roma, Italy.

    • A.A. Alves Jr,
    • G. Auriemma,
    • V. Bocci,
    • G. Martellotti,
    • G. Penso,
    • D. Pinci,
    • R. Santacesaria,
    • C. Satriano &
    • A. Sciubba
  285. Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland.

    • M. Kucharczyk,
    • A. Dziurda,
    • W. Kucewicz,
    • T. Lesiak,
    • B. Rachwal,
    • M. Witek &
    • M. Chrzaszcz
  286. AGH - University of Science and Technology, Faculty of Physics and Applied Computer Science, Kraków, Poland.

    • M. Firlej,
    • T. Fiutowski,
    • M. Idzik,
    • P. Morawski,
    • J. Moron,
    • A. Oblakowska-Mucha,
    • K. Swientek &
    • T. Szumlak
  287. National Center for Nuclear Research (NCBJ), Warsaw, Poland.

    • V. Batozskaya,
    • K. Klimaszewski,
    • K. Kurek,
    • M. Szczekowski,
    • A. Ukleja &
    • W. Wislicki
  288. Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania.

    • L. Cojocariu,
    • L. Giubega,
    • A. Grecu,
    • F. Maciuc,
    • M. Orlandea,
    • B. Popovici,
    • S. Stoica &
    • M. Straticiuc
  289. Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia.

    • G. Alkhazov,
    • N. Bondar,
    • A. Dzyuba,
    • O. Maev,
    • N. Sagidova,
    • Y. Shcheglov &
    • A. Vorobyev
  290. Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia.

    • S. Belogurov,
    • I. Belyaev,
    • V. Egorychev,
    • D. Golubkov,
    • T. Kvaratskheliya,
    • I.V. Machikhiliyan,
    • I. Polyakov,
    • D. Savrina,
    • A. Semennikov,
    • A. Zhokhov &
    • A. Golutvin
  291. Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow, Russia.

    • D. Savrina,
    • A. Berezhnoy,
    • M. Korolev,
    • A. Leflat &
    • N. Nikitin
  292. Institute for Nuclear Research of the Russian Academy of Sciences (INR RAN), Moscow, Russia.

    • S. Filippov,
    • E. Gushchin &
    • L. Kravchuk
  293. Budker Institute of Nuclear Physics (SB RAS) and Novosibirsk State University, Novosibirsk, Russia.

    • A. Bondar,
    • S. Eidelman,
    • P. Krokovny,
    • V. Kudryavtsev,
    • L. Shekhtman,
    • V. Vorobyev &
    • A. Poluektov
  294. Institute for High Energy Physics (IHEP), Protvino, Russia.

    • A. Artamonov,
    • K. Belous,
    • R. Dzhelyadin,
    • Yu. Guz,
    • A. Novoselov,
    • V. Obraztsov,
    • A. Popov,
    • V. Romanovsky,
    • M. Shapkin,
    • O. Stenyakin &
    • O. Yushchenko
  295. Universitat de Barcelona, Barcelona, Spain.

    • A. Badalov,
    • M. Calvo Gomez,
    • L. Garrido,
    • D. Gascon,
    • R. Graciani Diaz,
    • E. Graugés,
    • C. Marin Benito,
    • E. Picatoste Olloqui,
    • V. Rives Molina,
    • H. Ruiz &
    • X. Vilasis-Cardona
  296. Universidad de Santiago de Compostela, Santiago de Compostela, Spain.

    • B. Adeva,
    • P. Alvarez Cartelle,
    • A. Dosil Suárez,
    • V. Fernandez Albor,
    • A. Gallas Torreira,
    • J. García Pardiñas,
    • J.A. Hernando Morata,
    • M. Plo Casasus,
    • A. Romero Vidal,
    • J.J. Saborido Silva,
    • B. Sanmartin Sedes,
    • C. Santamarina Rios,
    • P. Vazquez Regueiro,
    • C. Vázquez Sierra &
    • M. Vieites Diaz
  297. European Organization for Nuclear Research (CERN), Geneva, Switzerland.

    • W. Bonivento,
    • A. Contu,
    • R. Cardinale,
    • B. Khanji,
    • J. Fu,
    • S. Gallorini,
    • A.A. Alves Jr,
    • A. Oblakowska-Mucha,
    • N. Bondar,
    • Yu. Guz,
    • F. Alessio,
    • F. Archilli,
    • C. Barschel,
    • S. Benson,
    • J. Buytaert,
    • D. Campora Perez,
    • L. Castillo Garcia,
    • M. Cattaneo,
    • Ph. Charpentier,
    • X. Cid Vidal,
    • M. Clemencic,
    • J. Closier,
    • V. Coco,
    • P. Collins,
    • G. Corti,
    • B. Couturier,
    • C. D'Ambrosio,
    • F. Dettori,
    • A. Di Canto,
    • H. Dijkstra,
    • P. Durante,
    • M. Ferro-Luzzi,
    • R. Forty,
    • M. Frank,
    • C. Frei,
    • C. Gaspar,
    • V.V. Gligorov,
    • L.A. Granado Cardoso,
    • T. Gys,
    • C. Haen,
    • J. He,
    • T. Head,
    • E. van Herwijnen,
    • R. Jacobsson,
    • D. Johnson,
    • C. Joram,
    • B. Jost,
    • M. Karacson,
    • T.M. Karbach,
    • D. Lacarrere,
    • B. Langhans,
    • R. Lindner,
    • C. Linn,
    • S. Lohn,
    • A. Mapelli,
    • R. Matev,
    • Z. Mathe,
    • S. Neubert,
    • N. Neufeld,
    • A. Otto,
    • J. Panman,
    • M. Pepe Altarelli,
    • N. Rauschmayr,
    • M. Rihl,
    • S. Roiser,
    • T. Ruf,
    • H. Schindler,
    • B. Schmidt,
    • A. Schopper,
    • R. Schwemmer,
    • S. Sridharan,
    • F. Stagni,
    • V.K. Subbiah,
    • F. Teubert,
    • E. Thomas,
    • D. Tonelli,
    • A. Trisovic,
    • M. Ubeda Garcia,
    • J. Wicht,
    • K. Wyllie,
    • P. Szczypka,
    • P. Koppenburg,
    • D. Martinez Santos,
    • S. Easo,
    • A. Papanestis,
    • A. Golutvin &
    • G. Wilkinson
  298. Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.

    • V. Battista,
    • A. Bay,
    • F. Blanc,
    • M. Dorigo,
    • F. Dupertuis,
    • C. Fitzpatrick,
    • S. Gianì,
    • G. Haefeli,
    • P. Jaton,
    • C. Khurewathanakul,
    • I. Komarov,
    • V.N. La Thi,
    • N. Lopez-March,
    • R. Märki,
    • M. Martinelli,
    • B. Muster,
    • T. Nakada,
    • A.D. Nguyen,
    • T.D. Nguyen,
    • C. Nguyen-Mau,
    • J. Prisciandaro,
    • A. Puig Navarro,
    • B. Rakotomiaramanana,
    • J. Rouvinet,
    • O. Schneider,
    • F. Soomro,
    • P. Szczypka,
    • M. Tobin,
    • S. Tourneur,
    • M.T. Tran,
    • G. Veneziano &
    • Z. Xu
  299. Physik-Institut, Universität Zürich, Zürich, Switzerland.

    • J. Anderson,
    • R. Bernet,
    • E. Bowen,
    • A. Bursche,
    • N. Chiapolini,
    • M. Chrzaszcz,
    • Ch. Elsasser,
    • E. Graverini,
    • F. Lionetto,
    • P. Lowdon,
    • K. Müller,
    • N. Serra,
    • O. Steinkamp,
    • B. Storaci,
    • U. Straumann,
    • M. Tresch &
    • A. Vollhardt
  300. Nikhef National Institute for Subatomic Physics, Amsterdam, The Netherlands.

    • R. Aaij,
    • S. Ali,
    • M. van Beuzekom,
    • P.N.Y. David,
    • K. De Bruyn,
    • C. Farinelli,
    • V. Heijne,
    • W. Hulsbergen,
    • E. Jans,
    • P. Koppenburg,
    • A. Kozlinskiy,
    • J. van Leerdam,
    • M. Merk,
    • S. Oggero,
    • A. Pellegrino,
    • H. Snoek,
    • J. van Tilburg,
    • P. Tsopelas,
    • N. Tuning &
    • J.A. de Vries
  301. Nikhef National Institute for Subatomic Physics and VU University Amsterdam, Amsterdam, The Netherlands.

    • T. Ketel,
    • R.F. Koopman,
    • R.W. Lambert,
    • D. Martinez Santos,
    • G. Raven,
    • M. Schiller,
    • V. Syropoulos &
    • S. Tolk
  302. NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine.

    • I. Shapoval,
    • A. Dovbnya,
    • S. Kandybei &
    • I. Raniuk
  303. Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine.

    • O. Okhrimenko &
    • V. Pugatch
  304. University of Birmingham, Birmingham, United Kingdom.

    • C.J. Parkinson,
    • S. Bifani,
    • N. Farley,
    • P. Griffith,
    • I.R. Kenyon,
    • C. Lazzeroni,
    • A. Mazurov,
    • J. McCarthy,
    • L. Pescatore,
    • N.K. Watson &
    • M.P. Williams
  305. H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom.

    • M. Adinolfi,
    • J. Benton,
    • N.H. Brook,
    • A. Cook,
    • M. Coombes,
    • J. Dalseno,
    • T. Hampson,
    • S.T. Harnew,
    • P. Naik,
    • E. Price,
    • C. Prouve,
    • J.H. Rademacker,
    • S. Richards,
    • D.M. Saunders,
    • N. Skidmore,
    • D. Souza,
    • J.J. Velthuis &
    • D. Voong
  306. Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom.

    • W. Barter,
    • M.-O. Bettler,
    • H.V. Cliff,
    • H.-M. Evans,
    • J. Garra Tico,
    • V. Gibson,
    • S. Gregson,
    • S.C. Haines,
    • C.R. Jones,
    • M. Sirendi,
    • J. Smith,
    • D.R. Ward,
    • S.A. Wotton &
    • S. Wright
  307. Department of Physics, University of Warwick, Coventry, United Kingdom.

    • J.J. Back,
    • T. Blake,
    • D.C. Craik,
    • A.C. Crocombe,
    • D. Dossett,
    • T. Gershon,
    • M. Kreps,
    • C. Langenbruch,
    • T. Latham,
    • D.P. O'Hanlon,
    • T. Pilař,
    • A. Poluektov,
    • M.M. Reid,
    • R. Silva Coutinho,
    • C. Wallace &
    • M. Whitehead
  308. STFC Rutherford Appleton Laboratory, Didcot, United Kingdom.

    • S. Easo,
    • R. Nandakumar,
    • A. Papanestis,
    • S. Ricciardi &
    • F.F. Wilson
  309. School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom.

    • L. Carson,
    • P.E.L. Clarke,
    • G.A. Cowan,
    • S. Eisenhardt,
    • D. Ferguson,
    • D. Lambert,
    • H. Luo,
    • A.-B. Morris,
    • F. Muheim,
    • M. Needham &
    • S. Playfer
  310. School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom.

    • M. Alexander,
    • J. Beddow,
    • C.-T. Dean,
    • L. Eklund,
    • D. Hynds,
    • S. Karodia,
    • I. Longstaff,
    • S. Ogilvy,
    • M. Pappagallo,
    • P. Sail,
    • I. Skillicorn,
    • F.J.P. Soler &
    • P. Spradlin
  311. Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom.

    • A. Affolder,
    • T.J.V. Bowcock,
    • H. Brown,
    • G. Casse,
    • S. Donleavy,
    • K. Dreimanis,
    • S. Farry,
    • R. Fay,
    • K. Hennessy,
    • D. Hutchcroft,
    • M. Liles,
    • B. McSkelly,
    • G.D. Patel,
    • J.D. Price,
    • A. Pritchard,
    • K. Rinnert,
    • T. Shears &
    • N.A. Smith
  312. Imperial College London, London, United Kingdom.

    • G. Ciezarek,
    • S. Cunliffe,
    • R. Currie,
    • U. Egede,
    • P. Fol,
    • A. Golutvin,
    • S. Hall,
    • M. McCann,
    • P. Owen,
    • M. Patel,
    • K. Petridis,
    • F. Redi,
    • I. Sepp,
    • E. Smith,
    • W. Sutcliffe &
    • D. Websdale
  313. School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom.

    • R.B. Appleby,
    • R.J. Barlow,
    • T. Bird,
    • P.M. Bjørnstad,
    • S. Borghi,
    • D. Brett,
    • J. Brodzicka,
    • L. Capriotti,
    • S. Chen,
    • S. De Capua,
    • G. Dujany,
    • M. Gersabeck,
    • J. Harrison,
    • C. Hombach,
    • S. Klaver,
    • G. Lafferty,
    • A. McNab,
    • C. Parkes,
    • A. Pearce,
    • S. Reichert,
    • E. Rodrigues,
    • P. Rodriguez Perez &
    • M. Smith
  314. Department of Physics, University of Oxford, Oxford, United Kingdom.

    • S.-F. Cheung,
    • D. Derkach,
    • T. Evans,
    • R. Gauld,
    • E. Greening,
    • N. Harnew,
    • D. Hill,
    • P. Hunt,
    • N. Hussain,
    • J. Jalocha,
    • M. John,
    • O. Lupton,
    • S. Malde,
    • E. Smith,
    • S. Stevenson,
    • C. Thomas,
    • S. Topp-Joergensen,
    • N. Torr &
    • G. Wilkinson
  315. Massachusetts Institute of Technology, Cambridge, MA, United States.

    • I. Counts,
    • P. Ilten &
    • M. Williams
  316. University of Cincinnati, Cincinnati, OH, United States.

    • R. Andreassen,
    • A. Davis,
    • W. De Silva,
    • B. Meadows,
    • M.D. Sokoloff,
    • L. Sun &
    • J. Todd
  317. University of Maryland, College Park, MD, United States.

    • J.E. Andrews,
    • B. Hamilton,
    • A. Jawahery &
    • J. Wimberley
  318. Syracuse University, Syracuse, NY, United States.

    • M. Artuso,
    • S. Blusk,
    • A. Borgia,
    • T. Britton,
    • S. Ely,
    • P. Gandini,
    • J. Garofoli,
    • B. Gui,
    • C. Hadjivasiliou,
    • N. Jurik,
    • M. Kelsey,
    • R. Mountain,
    • B.K. Pal,
    • T. Skwarnicki,
    • S. Stone,
    • J. Wang,
    • Z. Xing &
    • L. Zhang
  319. Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil; Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.

    • C. Baesso,
    • M. Cruz Torres,
    • C. Göbel &
    • J. Molina Rodriguez
  320. Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China; Center for High Energy Physics, Tsinghua University, Beijing, China.

    • Y. Xie
  321. Departamento de Fisica, Universidad Nacional de Colombia, Bogota, Colombia; LPNHE, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris, France.

    • D.A. Milanes
  322. Institut für Physik, Universität Rostock, Rostock, Germany; Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany.

    • O. Grünberg,
    • M. Heß,
    • C. Voß &
    • R. Waldi
  323. National Research Centre Kurchatov Institute, Moscow, Russia; Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia.

    • T. Likhomanenko,
    • A. Malinin,
    • V. Shevchenko &
    • A. Ustyuzhanin
  324. Instituto de Fisica Corpuscular (IFIC), Universitat de Valencia-CSIC, Valencia, Spain; Universitat de Barcelona, Barcelona, Spain.

    • F. Martinez Vidal,
    • A. Oyanguren,
    • P. Ruiz Valls &
    • C. Sanchez Mayordomo
  325. Van Swinderen Institute, University of Groningen, Groningen, The Netherlands; Nikhef National Institute for Subatomic Physics, Amsterdam, The Netherlands.

    • C.J.G. Onderwater &
    • H.W. Wilschut
  326. Celal Bayar University, Manisa, Turkey; European Organization for Nuclear Research (CERN), Geneva, Switzerland.

    • E. Pesen
  327. Università di Firenze, Firenze, Italy.

    • L. Anderlini &
    • M. Frosini
  328. Università di Ferrara, Ferrara, Italy.

    • M. Andreotti,
    • R. Calabrese,
    • M. Corvo,
    • M. Fiore,
    • M. Fiorini,
    • E. Luppi,
    • L.L. Pappalardo,
    • I. Shapoval,
    • G. Tellarini &
    • L. Tomassetti
  329. Università della Basilicata, Potenza, Italy.

    • G. Auriemma &
    • C. Satriano
  330. Università di Modena e Reggio Emilia, Modena, Italy.

    • A. Bizzeti
  331. Università di Milano Bicocca, Milano, Italy.

    • M. Calvi,
    • L. Cassina,
    • C. Gotti,
    • B. Khanji &
    • M. Kucharczyk
  332. LIFAELS, La Salle, Universitat Ramon Llull, Barcelona, Spain.

    • M. Calvo Gomez &
    • X. Vilasis-Cardona
  333. Università di Bologna, Bologna, Italy.

    • A. Carbone,
    • D. Galli &
    • S. Perazzini
  334. Università di Roma Tor Vergata, Roma, Italy.

    • G. Carboni,
    • E. Furfaro &
    • E. Santovetti
  335. Università di Genova, Genova, Italy.

    • R. Cardinale,
    • F. Fontanelli,
    • S. Gambetta,
    • C. Patrignani &
    • A. Petrolini
  336. Scuola Normale Superiore, Pisa, Italy.

    • R. Cenci,
    • P. Marino,
    • M.J. Morello &
    • S. Stracka
  337. Politecnico di Milano, Milano, Italy.

    • A. Geraci
  338. Universidade Federal do Triângulo Mineiro (UFTM), Uberaba-MG, Brazil.

    • A. Gomes
  339. AGH - University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, Kraków, Poland.

    • W. Kucewicz
  340. Università di Padova, Padova, Italy.

    • D. Lucchesi
  341. Università di Cagliari, Cagliari, Italy.

    • G. Manca,
    • R. Oldeman &
    • B. Saitta
  342. Hanoi University of Science, Hanoi, Viet Nam.

    • C. Nguyen-Mau
  343. Università di Bari, Bari, Italy.

    • A. Palano
  344. Università degli Studi di Milano, Milano, Italy.

    • F. Palombo
  345. Università di Roma La Sapienza, Roma, Italy.

    • A. Sarti,
    • G. Penso &
    • A. Sciubba
  346. Università di Pisa, Pisa, Italy.

    • G. Punzi
  347. Università di Urbino, Urbino, Italy.

    • M. Veltri
  348. P.N. Lebedev Physical Institute, Russian Academy of Science (LPI RAS), Moscow, Russia.

    • M. Zavertyaev
  349. Deceased.

    • P. Sharp &
    • S. Kwan

Consortia

  1. CMS Collaboration

    • V. Khachatryan,
    • A.M. Sirunyan,
    • A. Tumasyan,
    • W. Adam,
    • T. Bergauer,
    • M. Dragicevic,
    • J. Erö,
    • M. Friedl,
    • R. Frühwirth,
    • V.M. Ghete,
    • C. Hartl,
    • N. Hörmann,
    • J. Hrubec,
    • M. Jeitler,
    • W. Kiesenhofer,
    • V. Knünz,
    • M. Krammer,
    • I. Krätschmer,
    • D. Liko,
    • I. Mikulec,
    • D. Rabady,
    • B. Rahbaran,
    • H. Rohringer,
    • R. Schöfbeck,
    • J. Strauss,
    • W. Treberer-Treberspurg,
    • W. Waltenberger,
    • C.-E. Wulz,
    • V. Mossolov,
    • N. Shumeiko,
    • J. Suarez Gonzalez,
    • S. Alderweireldt,
    • S. Bansal,
    • T. Cornelis,
    • E.A. De Wolf,
    • X. Janssen,
    • A. Knutsson,
    • J. Lauwers,
    • S. Luyckx,
    • S. Ochesanu,
    • R. Rougny,
    • M. Van De Klundert,
    • H. Van Haevermaet,
    • P. Van Mechelen,
    • N. Van Remortel,
    • A. Van Spilbeeck,
    • F. Blekman,
    • S. Blyweert,
    • J. D'Hondt,
    • N. Daci,
    • N. Heracleous,
    • J. Keaveney,
    • S. Lowette,
    • M. Maes,
    • A. Olbrechts,
    • Q. Python,
    • D. Strom,
    • S. Tavernier,
    • W. Van Doninck,
    • P. Van Mulders,
    • G.P. Van Onsem,
    • I. Villella,
    • C. Caillol,
    • B. Clerbaux,
    • G. De Lentdecker,
    • D. Dobur,
    • L. Favart,
    • A.P.R. Gay,
    • A. Grebenyuk,
    • A. Léonard,
    • A. Mohammadi,
    • L. Perniè,
    • A. Randle-conde,
    • T. Reis,
    • T. Seva,
    • L. Thomas,
    • C. Vander Velde,
    • P. Vanlaer,
    • J. Wang,
    • F. Zenoni,
    • V. Adler,
    • K. Beernaert,
    • L. Benucci,
    • A. Cimmino,
    • S. Costantini,
    • S. Crucy,
    • S. Dildick,
    • A. Fagot,
    • G. Garcia,
    • J. Mccartin,
    • A.A. Ocampo Rios,
    • D. Ryckbosch,
    • S. Salva Diblen,
    • M. Sigamani,
    • N. Strobbe,
    • F. Thyssen,
    • M. Tytgat,
    • E. Yazgan,
    • N. Zaganidis,
    • S. Basegmez,
    • C. Beluffi,
    • G. Bruno,
    • R. Castello,
    • A. Caudron,
    • L. Ceard,
    • G.G. Da Silveira,
    • C. Delaere,
    • T. du Pree,
    • D. Favart,
    • L. Forthomme,
    • A. Giammanco,
    • J. Hollar,
    • A. Jafari,
    • P. Jez,
    • M. Komm,
    • V. Lemaitre,
    • C. Nuttens,
    • D. Pagano,
    • L. Perrini,
    • A. Pin,
    • K. Piotrzkowski,
    • A. Popov,
    • L. Quertenmont,
    • M. Selvaggi,
    • M. Vidal Marono,
    • J.M. Vizan Garcia,
    • N. Beliy,
    • T. Caebergs,
    • E. Daubie,
    • G.H. Hammad,
    • W.L. Aldá Júnior,
    • G.A. Alves,
    • L. Brito,
    • M. Correa Martins Junior,
    • T. Dos Reis Martins,
    • C. Mora Herrera,
    • M.E. Pol,
    • P. Rebello Teles,
    • W. Carvalho,
    • J. Chinellato,
    • A. Custódio,
    • E.M. Da Costa,
    • D. De Jesus Damiao,
    • C. De Oliveira Martins,
    • S. Fonseca De Souza,
    • H. Malbouisson,
    • D. Matos Figueiredo,
    • L. Mundim,
    • H. Nogima,
    • W.L. Prado Da Silva,
    • J. Santaolalla,
    • A. Santoro,
    • A. Sznajder,
    • E.J. Tonelli Manganote,
    • A. Vilela Pereira,
    • C.A. Bernardes,
    • S. Dogra,
    • T.R. Fernandez Perez Tomei,
    • E.M. Gregores,
    • P.G. Mercadante,
    • S.F. Novaes,
    • Sandra S. Padula,
    • A. Aleksandrov,
    • V. Genchev,
    • R. Hadjiiska,
    • P. Iaydjiev,
    • A. Marinov,
    • S. Piperov,
    • M. Rodozov,
    • G. Sultanov,
    • M. Vutova,
    • A. Dimitrov,
    • I. Glushkov,
    • L. Litov,
    • B. Pavlov,
    • P. Petkov,
    • J.G. Bian,
    • G.M. Chen,
    • H.S. Chen,
    • M. Chen,
    • T. Cheng,
    • R. Du,
    • C.H. Jiang,
    • R. Plestina,
    • F. Romeo,
    • J. Tao,
    • Z. Wang,
    • C. Asawatangtrakuldee,
    • Y. Ban,
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    • D. Wang,
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    • J.C. Sanabria,
    • N. Godinovic,
    • D. Lelas,
    • D. Polic,
    • I. Puljak,
    • Z. Antunovic,
    • M. Kovac,
    • V. Brigljevic,
    • K. Kadija,
    • J. Luetic,
    • D. Mekterovic,
    • L. Sudic,
    • A. Attikis,
    • G. Mavromanolakis,
    • J. Mousa,
    • C. Nicolaou,
    • F. Ptochos,
    • P.A. Razis,
    • M. Bodlak,
    • M. Finger,
    • M. Finger Jr.,
    • Y. Assran,
    • A. Ellithi Kamel,
    • M.A. Mahmoud,
    • A. Radi,
    • M. Kadastik,
    • M. Murumaa,
    • M. Raidal,
    • A. Tiko,
    • P. Eerola,
    • G. Fedi,
    • M. Voutilainen,
    • J. Härkönen,
    • V. Karimäki,
    • R. Kinnunen,
    • M.J. Kortelainen,
    • T. Lampén,
    • K. Lassila-Perini,
    • S. Lehti,
    • T. Lindén,
    • P. Luukka,
    • T. Mäenpää,
    • T. Peltola,
    • E. Tuominen,
    • J. Tuominiemi,
    • E. Tuovinen,
    • L. Wendland,
    • J. Talvitie,
    • T. Tuuva,
    • M. Besancon,
    • F. Couderc,
    • M. Dejardin,
    • D. Denegri,
    • B. Fabbro,
    • J.L. Faure,
    • C. Favaro,
    • F. Ferri,
    • S. Ganjour,
    • A. Givernaud,
    • P. Gras,
    • G. Hamel de Monchenault,
    • P. Jarry,
    • E. Locci,
    • J. Malcles,
    • J. Rander,
    • A. Rosowsky,
    • M. Titov,
    • S. Baffioni,
    • F. Beaudette,
    • P. Busson,
    • C. Charlot,
    • T. Dahms,
    • M. Dalchenko,
    • L. Dobrzynski,
    • N. Filipovic,
    • A. Florent,
    • R. Granier de Cassagnac,
    • L. Mastrolorenzo,
    • P. Miné,
    • C. Mironov,
    • I.N. Naranjo,
    • M. Nguyen,
    • C. Ochando,
    • G. Ortona,
    • P. Paganini,
    • S. Regnard,
    • R. Salerno,
    • J.B. Sauvan,
    • Y. Sirois,
    • C. Veelken,
    • Y. Yilmaz,
    • A. Zabi,
    • J.-L. Agram,
    • J. Andrea,
    • A. Aubin,
    • D. Bloch,
    • J.-M. Brom,
    • E.C. Chabert,
    • C. Collard,
    • E. Conte,
    • J.-C. Fontaine,
    • D. Gelé,
    • U. Goerlach,
    • C. Goetzmann,
    • A.-C. Le Bihan,
    • K. Skovpen,
    • P. Van Hove,
    • S. Gadrat,
    • S. Beauceron,
    • N. Beaupere,
    • G. Boudoul,
    • E. Bouvier,
    • S. Brochet,
    • C.A. Carrillo Montoya,
    • J. Chasserat,
    • R. Chierici,
    • D. Contardo,
    • P. Depasse,
    • H. El Mamouni,
    • J. Fan,
    • J. Fay,
    • S. Gascon,
    • M. Gouzevitch,
    • B. Ille,
    • T. Kurca,
    • M. Lethuillier,
    • L. Mirabito,
    • S. Perries,
    • J.D. Ruiz Alvarez,
    • D. Sabes,
    • L. Sgandurra,
    • V. Sordini,
    • M. Vander Donckt,
    • P. Verdier,
    • S. Viret,
    • H. Xiao,
    • Z. Tsamalaidze,
    • C. Autermann,
    • S. Beranek,
    • M. Bontenackels,
    • M. Edelhoff,
    • L. Feld,
    • A. Heister,
    • O. Hindrichs,
    • K. Klein,
    • A. Ostapchuk,
    • F. Raupach,
    • J. Sammet,
    • S. Schael,
    • J.F. Schulte,
    • H. Weber,
    • B. Wittmer,
    • V. Zhukov,
    • M. Ata,
    • M. Brodski,
    • E. Dietz-Laursonn,
    • D. Duchardt,
    • M. Erdmann,
    • R. Fischer,
    • A. Güth,
    • T. Hebbeker,
    • C. Heidemann,
    • K. Hoepfner,
    • D. Klingebiel,
    • S. Knutzen,
    • P. Kreuzer,
    • M. Merschmeyer,
    • A. Meyer,
    • P. Millet,
    • M. Olschewski,
    • K. Padeken,
    • P. Papacz,
    • H. Reithler,
    • S.A. Schmitz,
    • L. Sonnenschein,
    • D. Teyssier,
    • S. Thüer,
    • M. Weber,
    • V. Cherepanov,
    • Y. Erdogan,
    • G. Flügge,
    • H. Geenen,
    • M. Geisler,
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    • F. Hoehle,
    • B. Kargoll,
    • T. Kress,
    • Y. Kuessel,
    • A. Künsken,
    • J. Lingemann,
    • A. Nowack,
    • I.M. Nugent,
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    • A. Stahl,
    • M. Aldaya Martin,
    • I. Asin,
    • N. Bartosik,
    • J. Behr,
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    • A. Bethani,
    • K. Borras,
    • A. Burgmeier,
    • A. Cakir,
    • L. Calligaris,
    • A. Campbell,
    • S. Choudhury,
    • F. Costanza,
    • C. Diez Pardos,
    • G. Dolinska,
    • S. Dooling,
    • T. Dorland,
    • G. Eckerlin,
    • D. Eckstein,
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    • G. Flucke,
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    • A. Geiser,
    • P. Gunnellini,
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    • A. Kalogeropoulos,
    • M. Kasemann,
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    • D. Krücker,
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    • A. Lobanov,
    • W. Lohmann,
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    • A.B. Meyer,
    • G. Mittag,
    • J. Mnich,
    • A. Mussgiller,
    • S. Naumann-Emme,
    • A. Nayak,
    • E. Ntomari,
    • H. Perrey,
    • D. Pitzl,
    • R. Placakyte,
    • A. Raspereza,
    • P.M. Ribeiro Cipriano,
    • B. Roland,
    • E. Ron,
    • M.Ö. Sahin,
    • J. Salfeld-Nebgen,
    • P. Saxena,
    • T. Schoerner-Sadenius,
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    • S. Spannagel,
    • A.D.R. Vargas Trevino,
    • R. Walsh,
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    • V. Blobel,
    • M. Centis Vignali,
    • A.R. Draeger,
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    • J. Haller,
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    • R. Kogler,
    • J. Lange,
    • T. Lapsien,
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    • I. Marchesini,
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    • T. Peiffer,
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    • N. Pietsch,
    • J. Poehlsen,
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    • E. Schlieckau,
    • A. Schmidt,
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    • G. Steinbrück,
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    • C. Barth,
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    • A. Dierlamm,
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    • F. Hartmann,
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    • P. Lobelle Pardo,
    • M.U. Mozer,
    • T. Müller,
    • Th. Müller,
    • A. Nürnberg,
    • G. Quast,
    • K. Rabbertz,
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    • H.J. Simonis,
    • F.M. Stober,
    • R. Ulrich,
    • J. Wagner-Kuhr,
    • S. Wayand,
    • T. Weiler,
    • R. Wolf,
    • G. Anagnostou,
    • G. Daskalakis,
    • T. Geralis,
    • V.A. Giakoumopoulou,
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    • A. Psallidas,
    • I. Topsis-Giotis,
    • A. Agapitos,
    • S. Kesisoglou,
    • A. Panagiotou,
    • N. Saoulidou,
    • E. Stiliaris,
    • X. Aslanoglou,
    • I. Evangelou,
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    • G. Vesztergombi,
    • A.J. Zsigmond,
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    • S. Czellar,
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    • J. Palinkas,
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    • B. Ujvari,
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    • S.K. Swain,
    • S.B. Beri,
    • V. Bhatnagar,
    • R. Gupta,
    • U. Bhawandeep,
    • A.K. Kalsi,
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    • J.B. Singh,
    • Ashok Kumar,
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    • A. Bhardwaj,
    • B.C. Choudhary,
    • A. Kumar,
    • S. Malhotra,
    • M. Naimuddin,
    • K. Ranjan,
    • V. Sharma,
    • S. Banerjee,
    • S. Bhattacharya,
    • K. Chatterjee,
    • S. Dutta,
    • B. Gomber,
    • Sa. Jain,
    • Sh. Jain,
    • R. Khurana,
    • A. Modak,
    • S. Mukherjee,
    • D. Roy,
    • S. Sarkar,
    • M. Sharan,
    • A. Abdulsalam,
    • D. Dutta,
    • S. Kailas,
    • V. Kumar,
    • A.K. Mohanty,
    • L.M. Pant,
    • P. Shukla,
    • A. Topkar,
    • T. Aziz,
    • S. Banerjee,
    • S. Bhowmik,
    • R.M. Chatterjee,
    • R.K. Dewanjee,
    • S. Dugad,
    • S. Ganguly,
    • S. Ghosh,
    • M. Guchait,
    • A. Gurtu,
    • G. Kole,
    • S. Kumar,
    • M. Maity,
    • G. Majumder,
    • K. Mazumdar,
    • G.B. Mohanty,
    • B. Parida,
    • K. Sudhakar,
    • N. Wickramage,
    • H. Bakhshiansohi,
    • H. Behnamian,
    • S.M. Etesami,
    • A. Fahim,
    • R. Goldouzian,
    • M. Khakzad,
    • M. Mohammadi Najafabadi,
    • M. Naseri,
    • S. Paktinat Mehdiabadi,
    • F. Rezaei Hosseinabadi,
    • B. Safarzadeh,
    • M. Zeinali,
    • M. Felcini,
    • M. Grunewald,
    • M. Abbrescia,
    • C. Calabria,
    • S.S. Chhibra,
    • A. Colaleo,
    • D. Creanza,
    • N. De Filippis,
    • M. De Palma,
    • L. Fiore,
    • G. Iaselli,
    • G. Maggi,
    • M. Maggi,
    • S. My,
    • S. Nuzzo,
    • A. Pompili,
    • G. Pugliese,
    • R. Radogna,
    • G. Selvaggi,
    • A. Sharma,
    • L. Silvestris,
    • R. Venditti,
    • P. Verwilligen,
    • G. Abbiendi,
    • A.C. Benvenuti,
    • D. Bonacorsi,
    • S. Braibant-Giacomelli,
    • L. Brigliadori,
    • R. Campanini,
    • P. Capiluppi,
    • A. Castro,
    • F.R. Cavallo,
    • G. Codispoti,
    • M. Cuffiani,
    • G.M. Dallavalle,
    • F. Fabbri,
    • A. Fanfani,
    • D. Fasanella,
    • P. Giacomelli,
    • C. Grandi,
    • L. Guiducci,
    • S. Marcellini,
    • G. Masetti,
    • A. Montanari,
    • F.L. Navarria,
    • A. Perrotta,
    • F. Primavera,
    • A.M. Rossi,
    • T. Rovelli,
    • G.P. Siroli,
    • N. Tosi,
    • R. Travaglini,
    • S. Albergo,
    • G. Cappello,
    • M. Chiorboli,
    • S. Costa,
    • F. Giordano,
    • R. Potenza,
    • A. Tricomi,
    • C. Tuve,
    • G. Barbagli,
    • V. Ciulli,
    • C. Civinini,
    • R. D'Alessandro,
    • E. Focardi,
    • E. Gallo,
    • S. Gonzi,
    • V. Gori,
    • P. Lenzi,
    • M. Meschini,
    • S. Paoletti,
    • G. Sguazzoni,
    • A. Tropiano,
    • L. Benussi,
    • S. Bianco,
    • F. Fabbri,
    • D. Piccolo,
    • R. Ferretti,
    • F. Ferro,
    • M. Lo Vetere,
    • E. Robutti,
    • S. Tosi,
    • M.E. Dinardo,
    • S. Fiorendi,
    • S. Gennai,
    • R. Gerosa,
    • A. Ghezzi,
    • P. Govoni,
    • M.T. Lucchini,
    • S. Malvezzi,
    • R.A. Manzoni,
    • A. Martelli,
    • B. Marzocchi,
    • D. Menasce,
    • L. Moroni,
    • M. Paganoni,
    • D. Pedrini,
    • S. Ragazzi,
    • N. Redaelli,
    • T. Tabarelli de Fatis,
    • S. Buontempo,
    • N. Cavallo,
    • S. Di Guida,
    • F. Fabozzi,
    • A.O.M. Iorio,
    • L. Lista,
    • S. Meola,
    • M. Merola,
    • P. Paolucci,
    • P. Azzi,
    • N. Bacchetta,
    • D. Bisello,
    • A. Branca,
    • R. Carlin,
    • P. Checchia,
    • M. Dall'Osso,
    • T. Dorigo,
    • U. Dosselli,
    • M. Galanti,
    • F. Gasparini,
    • U. Gasparini,
    • P. Giubilato,
    • A. Gozzelino,
    • K. Kanishchev,
    • S. Lacaprara,
    • M. Margoni,
    • A.T. Meneguzzo,
    • J. Pazzini,
    • N. Pozzobon,
    • P. Ronchese,
    • F. Simonetto,
    • E. Torassa,
    • M. Tosi,
    • P. Zotto,
    • A. Zucchetta,
    • G. Zumerle,
    • M. Gabusi,
    • S.P. Ratti,
    • V. Re,
    • C. Riccardi,
    • P. Salvini,
    • P. Vitulo,
    • M. Biasini,
    • G.M. Bilei,
    • D. Ciangottini,
    • L. Fanò,
    • P. Lariccia,
    • G. Mantovani,
    • M. Menichelli,
    • A. Saha,
    • A. Santocchia,
    • A. Spiezia,
    • K. Androsov,
    • P. Azzurri,
    • G. Bagliesi,
    • J. Bernardini,
    • T. Boccali,
    • G. Broccolo,
    • R. Castaldi,
    • M.A. Ciocci,
    • R. Dell'Orso,
    • S. Donato,
    • F. Fiori,
    • L. Foà,
    • A. Giassi,
    • M.T. Grippo,
    • F. Ligabue,
    • T. Lomtadze,
    • L. Martini,
    • A. Messineo,
    • C.S. Moon,
    • F. Palla,
    • A. Rizzi,
    • A. Savoy-Navarro,
    • A.T. Serban,
    • P. Spagnolo,
    • P. Squillacioti,
    • R. Tenchini,
    • G. Tonelli,
    • A. Venturi,
    • P.G. Verdini,
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    • L. Barone,
    • F. Cavallari,
    • G. D'imperio,
    • D. Del Re,
    • M. Diemoz,
    • C. Jorda,
    • E. Longo,
    • F. Margaroli,
    • P. Meridiani,
    • F. Micheli,
    • S. Nourbakhsh,
    • G. Organtini,
    • R. Paramatti,
    • S. Rahatlou,
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    • F. Santanastasio,
    • L. Soffi,
    • P. Traczyk,
    • N. Amapane,
    • R. Arcidiacono,
    • S. Argiro,
    • M. Arneodo,
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    • C. Mariotti,
    • S. Maselli,
    • E. Migliore,
    • V. Monaco,
    • M. Musich,
    • M.M. Obertino,
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    • N. Pastrone,
    • M. Pelliccioni,
    • G.L. Pinna Angioni,
    • A. Potenza,
    • A. Romero,
    • M. Ruspa,
    • R. Sacchi,
    • A. Solano,
    • A. Staiano,
    • U. Tamponi,
    • S. Belforte,
    • V. Candelise,
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    • F. Cossutti,
    • G. Della Ricca,
    • B. Gobbo,
    • C. La Licata,
    • M. Marone,
    • A. Schizzi,
    • T. Umer,
    • A. Zanetti,
    • S. Chang,
    • A. Kropivnitskaya,
    • S.K. Nam,
    • D.H. Kim,
    • G.N. Kim,
    • M.S. Kim,
    • D.J. Kong,
    • S. Lee,
    • Y.D. Oh,
    • H. Park,
    • A. Sakharov,
    • D.C. Son,
    • T.J. Kim,
    • J.Y. Kim,
    • S. Song,
    • S. Choi,
    • D. Gyun,
    • B. Hong,
    • M. Jo,
    • H. Kim,
    • Y. Kim,
    • B. Lee,
    • K.S. Lee,
    • S.K. Park,
    • Y. Roh,
    • H.D. Yoo,
    • M. Choi,
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    • I.C. Park,
    • G. Ryu,
    • M.S. Ryu,
    • Y. Choi,
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    • J. Goh,
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    • I. Yu,
    • A. Juodagalvis,
    • J.R. Komaragiri,
    • M.A.B. Md Ali,
    • E. Casimiro Linares,
    • H. Castilla-Valdez,
    • E. De La Cruz-Burelo,
    • I. Heredia-de La Cruz,
    • A. Hernandez-Almada,
    • R. Lopez-Fernandez,
    • A. Sanchez-Hernandez,
    • S. Carrillo Moreno,
    • F. Vazquez Valencia,
    • I. Pedraza,
    • H.A. Salazar Ibarguen,
    • A. Morelos Pineda,
    • D. Krofcheck,
    • P.H. Butler,
    • S. Reucroft,
    • A. Ahmad,
    • M. Ahmad,
    • Q. Hassan,
    • H.R. Hoorani,
    • W.A. Khan,
    • T. Khurshid,
    • M. Shoaib,
    • H. Bialkowska,
    • M. Bluj,
    • B. Boimska,
    • T. Frueboes,
    • M. Górski,
    • M. Kazana,
    • K. Nawrocki,
    • K. Romanowska-Rybinska,
    • M. Szleper,
    • P. Zalewski,
    • G. Brona,
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    • M. Cwiok,
    • W. Dominik,
    • K. Doroba,
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    • I. Golutvin,
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    • A. Kamenev,
    • V. Karjavin,
    • V. Konoplyanikov,
    • A. Lanev,
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    • V. Matveev,
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    • Y. Ivanov,
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    • I. Pozdnyakov,
    • G. Safronov,
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    • V. Stolin,
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    • A. Leonidov,
    • G. Mesyats,
    • S.V. Rusakov,
    • A. Vinogradov,
    • A. Belyaev,
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    • M. Dubinin,
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    • A. Ershov,
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    • V. Klyukhin,
    • O. Kodolova,
    • I. Lokhtin,
    • S. Obraztsov,
    • S. Petrushanko,
    • V. Savrin,
    • A. Snigirev,
    • I. Azhgirey,
    • I. Bayshev,
    • S. Bitioukov,
    • V. Kachanov,
    • A. Kalinin,
    • D. Konstantinov,
    • V. Krychkine,
    • V. Petrov,
    • R. Ryutin,
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    • L. Tourtchanovitch,
    • S. Troshin,
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    • J. Alcaraz Maestre,
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    • A. Escalante Del Valle,
    • C. Fernandez Bedoya,
    • J.P. Fernández Ramos,
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    • A. Pérez-Calero Yzquierdo,
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    • S. Colafranceschi,
    • M. D'Alfonso,
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    • P.R. Hobson,
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    • S. Chauhan,
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    • S.C. Tonwar,
    • A. Apyan,
    • R. Barbieri,
    • G. Bauer,
    • W. Busza,
    • I.A. Cali,
    • M. Chan,
    • L. Di Matteo,
    • G. Gomez Ceballos,
    • M. Goncharov,
    • D. Gulhan,
    • M. Klute,
    • Y.S. Lai,
    • Y.-J. Lee,
    • A. Levin,
    • P.D. Luckey,
    • T. Ma,
    • C. Paus,
    • D. Ralph,
    • C. Roland,
    • G. Roland,
    • G.S.F. Stephans,
    • K. Sumorok,
    • D. Velicanu,
    • J. Veverka,
    • B. Wyslouch,
    • M. Yang,
    • M. Zanetti,
    • V. Zhukova,
    • B. Dahmes,
    • A. Gude,
    • S.C. Kao,
    • K. Klapoetke,
    • Y. Kubota,
    • J. Mans,
    • N. Pastika,
    • R. Rusack,
    • A. Singovsky,
    • N. Tambe,
    • J. Turkewitz,
    • J.G. Acosta,
    • S. Oliveros,
    • E. Avdeeva,
    • K. Bloom,
    • S. Bose,
    • D.R. Claes,
    • A. Dominguez,
    • R. Gonzalez Suarez,
    • J. Keller,
    • D. Knowlton,
    • I. Kravchenko,
    • J. Lazo-Flores,
    • F. Meier,
    • F. Ratnikov,
    • G.R. Snow,
    • M. Zvada,
    • J. Dolen,
    • A. Godshalk,
    • I. Iashvili,
    • A. Kharchilava,
    • A. Kumar,
    • S. Rappoccio,
    • G. Alverson,
    • E. Barberis,
    • D. Baumgartel,
    • M. Chasco,
    • A. Massironi,
    • D.M. Morse,
    • D. Nash,
    • T. Orimoto,
    • D. Trocino,
    • R.-J. Wang,
    • D. Wood,
    • J. Zhang,
    • K.A. Hahn,
    • A. Kubik,
    • N. Mucia,
    • N. Odell,
    • B. Pollack,
    • A. Pozdnyakov,
    • M. Schmitt,
    • S. Stoynev,
    • K. Sung,
    • M. Velasco,
    • S. Won,
    • A. Brinkerhoff,
    • K.M. Chan,
    • A. Drozdetskiy,
    • M. Hildreth,
    • C. Jessop,
    • D.J. Karmgard,
    • N. Kellams,
    • K. Lannon,
    • S. Lynch,
    • N. Marinelli,
    • Y. Musienko,
    • T. Pearson,
    • M. Planer,
    • R. Ruchti,
    • G. Smith,
    • N. Valls,
    • M. Wayne,
    • M. Wolf,
    • A. Woodard,
    • L. Antonelli,
    • J. Brinson,
    • B. Bylsma,
    • L.S. Durkin,
    • S. Flowers,
    • A. Hart,
    • C. Hill,
    • R. Hughes,
    • K. Kotov,
    • T.Y. Ling,
    • W. Luo,
    • D. Puigh,
    • M. Rodenburg,
    • B.L. Winer,
    • H. Wolfe,
    • H.W. Wulsin,
    • O. Driga,
    • P. Elmer,
    • J. Hardenbrook,
    • P. Hebda,
    • A. Hunt,
    • S.A. Koay,
    • P. Lujan,
    • D. Marlow,
    • T. Medvedeva,
    • M. Mooney,
    • J. Olsen,
    • P. Piroué,
    • X. Quan,
    • H. Saka,
    • D. Stickland,
    • C. Tully,
    • J.S. Werner,
    • A. Zuranski,
    • E. Brownson,
    • S. Malik,
    • H. Mendez,
    • J.E. Ramirez Vargas,
    • V.E. Barnes,
    • D. Benedetti,
    • D. Bortoletto,
    • M. De Mattia,
    • L. Gutay,
    • Z. Hu,
    • M.K. Jha,
    • M. Jones,
    • K. Jung,
    • M. Kress,
    • N. Leonardo,
    • D.H. Miller,
    • N. Neumeister,
    • B.C. Radburn-Smith,
    • X. Shi,
    • I. Shipsey,
    • D. Silvers,
    • A. Svyatkovskiy,
    • F. Wang,
    • W. Xie,
    • L. Xu,
    • J. Zablocki,
    • N. Parashar,
    • J. Stupak,
    • A. Adair,
    • B. Akgun,
    • K.M. Ecklund,
    • F.J.M. Geurts,
    • W. Li,
    • B. Michlin,
    • B.P. Padley,
    • R. Redjimi,
    • J. Roberts,
    • J. Zabel,
    • B. Betchart,
    • A. Bodek,
    • R. Covarelli,
    • P. de Barbaro,
    • R. Demina,
    • Y. Eshaq,
    • T. Ferbel,
    • A. Garcia-Bellido,
    • P. Goldenzweig,
    • J. Han,
    • A. Harel,
    • A. Khukhunaishvili,
    • S. Korjenevski,
    • G. Petrillo,
    • D. Vishnevskiy,
    • R. Ciesielski,
    • L. Demortier,
    • K. Goulianos,
    • C. Mesropian,
    • S. Arora,
    • A. Barker,
    • J.P. Chou,
    • C. Contreras-Campana,
    • E. Contreras-Campana,
    • D. Duggan,
    • D. Ferencek,
    • Y. Gershtein,
    • R. Gray,
    • E. Halkiadakis,
    • D. Hidas,
    • S. Kaplan,
    • A. Lath,
    • S. Panwalkar,
    • M. Park,
    • R. Patel,
    • S. Salur,
    • S. Schnetzer,
    • S. Somalwar,
    • R. Stone,
    • S. Thomas,
    • P. Thomassen,
    • M. Walker,
    • K. Rose,
    • S. Spanier,
    • A. York,
    • O. Bouhali,
    • A. Castaneda Hernandez,
    • R. Eusebi,
    • W. Flanagan,
    • J. Gilmore,
    • T. Kamon,
    • V. Khotilovich,
    • V. Krutelyov,
    • R. Montalvo,
    • I. Osipenkov,
    • Y. Pakhotin,
    • A. Perloff,
    • J. Roe,
    • A. Rose,
    • A. Safonov,
    • I. Suarez,
    • A. Tatarinov,
    • K.A. Ulmer,
    • N. Akchurin,
    • C. Cowden,
    • J. Damgov,
    • C. Dragoiu,
    • P.R. Dudero,
    • J. Faulkner,
    • K. Kovitanggoon,
    • S. Kunori,
    • S.W. Lee,
    • T. Libeiro,
    • I. Volobouev,
    • E. Appelt,
    • A.G. Delannoy,
    • S. Greene,
    • A. Gurrola,
    • W. Johns,
    • C. Maguire,
    • Y. Mao,
    • A. Melo,
    • M. Sharma,
    • P. Sheldon,
    • B. Snook,
    • S. Tuo,
    • J. Velkovska,
    • M.W. Arenton,
    • S. Boutle,
    • B. Cox,
    • B. Francis,
    • J. Goodell,
    • R. Hirosky,
    • A. Ledovskoy,
    • H. Li,
    • C. Lin,
    • C. Neu,
    • J. Wood,
    • C. Clarke,
    • R. Harr,
    • P.E. Karchin,
    • C. Kottachchi Kankanamge Don,
    • P. Lamichhane,
    • J. Sturdy,
    • D.A. Belknap,
    • D. Carlsmith,
    • M. Cepeda,
    • S. Dasu,
    • L. Dodd,
    • S. Duric,
    • E. Friis,
    • R. Hall-Wilton,
    • M. Herndon,
    • A. Hervé,
    • P. Klabbers,
    • A. Lanaro,
    • C. Lazaridis,
    • A. Levine,
    • R. Loveless,
    • A. Mohapatra,
    • I. Ojalvo,
    • T. Perry,
    • G.A. Pierro,
    • G. Polese,
    • I. Ross,
    • T. Sarangi,
    • A. Savin,
    • W.H. Smith,
    • D. Taylor,
    • C. Vuosalo &
    • N. Woods
  2. LHCb Collaboration

    • I. Bediaga,
    • J.M. De Miranda,
    • F. Ferreira Rodrigues,
    • A. Gomes,
    • A. Massafferri,
    • A.C. dos Reis,
    • A.B. Rodrigues,
    • S. Amato,
    • K. Carvalho Akiba,
    • L. De Paula,
    • O. Francisco,
    • M. Gandelman,
    • A. Hicheur,
    • J.H. Lopes,
    • D. Martins Tostes,
    • I. Nasteva,
    • J.M. Otalora Goicochea,
    • E. Polycarpo,
    • C. Potterat,
    • M.S. Rangel,
    • V. Salustino Guimaraes,
    • B. Souza De Paula,
    • D. Vieira,
    • L. An,
    • Y. Gao,
    • F. Jing,
    • Y. Li,
    • Z. Yang,
    • X. Yuan,
    • Y. Zhang,
    • L. Zhong,
    • L. Beaucourt,
    • M. Chefdeville,
    • D. Decamp,
    • N. Déléage,
    • Ph. Ghez,
    • J.-P. Lees,
    • J.F. Marchand,
    • M.-N. Minard,
    • B. Pietrzyk,
    • W. Qian,
    • S. T'Jampens,
    • V. Tisserand,
    • E. Tournefier,
    • Z. Ajaltouni,
    • M. Baalouch,
    • E. Cogneras,
    • O. Deschamps,
    • I. El Rifai,
    • M. Grabalosa Gándara,
    • P. Henrard,
    • M. Hoballah,
    • R. Lefèvre,
    • J. Maratas,
    • S. Monteil,
    • V. Niess,
    • P. Perret,
    • C. Adrover,
    • S. Akar,
    • E. Aslanides,
    • J. Cogan,
    • W. Kanso,
    • R. Le Gac,
    • O. Leroy,
    • G. Mancinelli,
    • A. Mordà,
    • M. Perrin-Terrin,
    • J. Serrano,
    • A. Tsaregorodtsev,
    • Y. Amhis,
    • S. Barsuk,
    • M. Borsato,
    • O. Kochebina,
    • J. Lefrançois,
    • F. Machefert,
    • A. Martín Sánchez,
    • M. Nicol,
    • P. Robbe,
    • M.-H. Schune,
    • M. Teklishyn,
    • A. Vallier,
    • B. Viaud,
    • G. Wormser,
    • E. Ben-Haim,
    • M. Charles,
    • S. Coquereau,
    • P. David,
    • L. Del Buono,
    • L. Henry,
    • F. Polci,
    • J. Albrecht,
    • T. Brambach,
    • Ch. Cauet,
    • M. Deckenhoff,
    • U. Eitschberger,
    • R. Ekelhof,
    • L. Gavardi,
    • F. Kruse,
    • F. Meier,
    • R. Niet,
    • C.J. Parkinson,
    • M. Schlupp,
    • A. Shires,
    • B. Spaan,
    • S. Swientek,
    • J. Wishahi,
    • O. Aquines Gutierrez,
    • J. Blouw,
    • M. Britsch,
    • M. Fontana,
    • D. Popov,
    • M. Schmelling,
    • D. Volyanskyy,
    • M. Zavertyaev,
    • S. Bachmann,
    • A. Bien,
    • A. Comerma-Montells,
    • M. De Cian,
    • F. Dordei,
    • S. Esen,
    • C. Färber,
    • E. Gersabeck,
    • L. Grillo,
    • X. Han,
    • S. Hansmann-Menzemer,
    • A. Jaeger,
    • M. Kolpin,
    • K. Kreplin,
    • G. Krocker,
    • B. Leverington,
    • J. Marks,
    • M. Meissner,
    • M. Neuner,
    • T. Nikodem,
    • P. Seyfert,
    • M. Stahl,
    • S. Stahl,
    • U. Uwer,
    • M. Vesterinen,
    • S. Wandernoth,
    • D. Wiedner,
    • A. Zhelezov,
    • R. McNulty,
    • R. Wallace,
    • W.C. Zhang,
    • A. Palano,
    • A. Carbone,
    • A. Falabella,
    • D. Galli,
    • U. Marconi,
    • N. Moggi,
    • M. Mussini,
    • S. Perazzini,
    • V. Vagnoni,
    • G. Valenti,
    • M. Zangoli,
    • W. Bonivento,
    • S. Cadeddu,
    • A. Cardini,
    • V. Cogoni,
    • A. Contu,
    • A. Lai,
    • B. Liu,
    • G. Manca,
    • R. Oldeman,
    • B. Saitta,
    • C. Vacca,
    • M. Andreotti,
    • W. Baldini,
    • C. Bozzi,
    • R. Calabrese,
    • M. Corvo,
    • M. Fiore,
    • M. Fiorini,
    • E. Luppi,
    • L.L. Pappalardo,
    • I. Shapoval,
    • G. Tellarini,
    • L. Tomassetti,
    • S. Vecchi,
    • L. Anderlini,
    • A. Bizzeti,
    • M. Frosini,
    • G. Graziani,
    • G. Passaleva,
    • M. Veltri,
    • G. Bencivenni,
    • P. Campana,
    • P. De Simone,
    • G. Lanfranchi,
    • M. Palutan,
    • M. Rama,
    • A. Sarti,
    • B. Sciascia,
    • R. Vazquez Gomez,
    • R. Cardinale,
    • F. Fontanelli,
    • S. Gambetta,
    • C. Patrignani,
    • A. Petrolini,
    • A. Pistone,
    • M. Calvi,
    • L. Cassina,
    • C. Gotti,
    • B. Khanji,
    • M. Kucharczyk,
    • C. Matteuzzi,
    • J. Fu,
    • A. Geraci,
    • N. Neri,
    • F. Palombo,
    • S. Amerio,
    • G. Collazuol,
    • S. Gallorini,
    • A. Gianelle,
    • D. Lucchesi,
    • A. Lupato,
    • M. Morandin,
    • M. Rotondo,
    • L. Sestini,
    • G. Simi,
    • R. Stroili,
    • F. Bedeschi,
    • R. Cenci,
    • S. Leo,
    • P. Marino,
    • M.J. Morello,
    • G. Punzi,
    • S. Stracka,
    • J. Walsh,
    • G. Carboni,
    • E. Furfaro,
    • E. Santovetti,
    • A. Satta,
    • A.A. Alves Jr,
    • G. Auriemma,
    • V. Bocci,
    • G. Martellotti,
    • G. Penso,
    • D. Pinci,
    • R. Santacesaria,
    • C. Satriano,
    • A. Sciubba,
    • A. Dziurda,
    • W. Kucewicz,
    • T. Lesiak,
    • B. Rachwal,
    • M. Witek,
    • M. Firlej,
    • T. Fiutowski,
    • M. Idzik,
    • P. Morawski,
    • J. Moron,
    • A. Oblakowska-Mucha,
    • K. Swientek,
    • T. Szumlak,
    • V. Batozskaya,
    • K. Klimaszewski,
    • K. Kurek,
    • M. Szczekowski,
    • A. Ukleja,
    • W. Wislicki,
    • L. Cojocariu,
    • L. Giubega,
    • A. Grecu,
    • F. Maciuc,
    • M. Orlandea,
    • B. Popovici,
    • S. Stoica,
    • M. Straticiuc,
    • G. Alkhazov,
    • N. Bondar,
    • A. Dzyuba,
    • O. Maev,
    • N. Sagidova,
    • Y. Shcheglov,
    • A. Vorobyev,
    • S. Belogurov,
    • I. Belyaev,
    • V. Egorychev,
    • D. Golubkov,
    • T. Kvaratskheliya,
    • I.V. Machikhiliyan,
    • I. Polyakov,
    • D. Savrina,
    • A. Semennikov,
    • A. Zhokhov,
    • A. Berezhnoy,
    • M. Korolev,
    • A. Leflat,
    • N. Nikitin,
    • S. Filippov,
    • E. Gushchin,
    • L. Kravchuk,
    • A. Bondar,
    • S. Eidelman,
    • P. Krokovny,
    • V. Kudryavtsev,
    • L. Shekhtman,
    • V. Vorobyev,
    • A. Artamonov,
    • K. Belous,
    • R. Dzhelyadin,
    • Yu. Guz,
    • A. Novoselov,
    • V. Obraztsov,
    • A. Popov,
    • V. Romanovsky,
    • M. Shapkin,
    • O. Stenyakin,
    • O. Yushchenko,
    • A. Badalov,
    • M. Calvo Gomez,
    • L. Garrido,
    • D. Gascon,
    • R. Graciani Diaz,
    • E. Graugés,
    • C. Marin Benito,
    • E. Picatoste Olloqui,
    • V. Rives Molina,
    • H. Ruiz,
    • X. Vilasis-Cardona,
    • B. Adeva,
    • P. Alvarez Cartelle,
    • A. Dosil Suárez,
    • V. Fernandez Albor,
    • A. Gallas Torreira,
    • J. García Pardiñas,
    • J.A. Hernando Morata,
    • M. Plo Casasus,
    • A. Romero Vidal,
    • J.J. Saborido Silva,
    • B. Sanmartin Sedes,
    • C. Santamarina Rios,
    • P. Vazquez Regueiro,
    • C. Vázquez Sierra,
    • M. Vieites Diaz,
    • F. Alessio,
    • F. Archilli,
    • C. Barschel,
    • S. Benson,
    • J. Buytaert,
    • D. Campora Perez,
    • L. Castillo Garcia,
    • M. Cattaneo,
    • Ph. Charpentier,
    • X. Cid Vidal,
    • M. Clemencic,
    • J. Closier,
    • V. Coco,
    • P. Collins,
    • G. Corti,
    • B. Couturier,
    • C. D'Ambrosio,
    • F. Dettori,
    • A. Di Canto,
    • H. Dijkstra,
    • P. Durante,
    • M. Ferro-Luzzi,
    • R. Forty,
    • M. Frank,
    • C. Frei,
    • C. Gaspar,
    • V.V. Gligorov,
    • L.A. Granado Cardoso,
    • T. Gys,
    • C. Haen,
    • J. He,
    • T. Head,
    • E. van Herwijnen,
    • R. Jacobsson,
    • D. Johnson,
    • C. Joram,
    • B. Jost,
    • M. Karacson,
    • T.M. Karbach,
    • D. Lacarrere,
    • B. Langhans,
    • R. Lindner,
    • C. Linn,
    • S. Lohn,
    • A. Mapelli,
    • R. Matev,
    • Z. Mathe,
    • S. Neubert,
    • N. Neufeld,
    • A. Otto,
    • J. Panman,
    • M. Pepe Altarelli,
    • N. Rauschmayr,
    • M. Rihl,
    • S. Roiser,
    • T. Ruf,
    • H. Schindler,
    • B. Schmidt,
    • A. Schopper,
    • R. Schwemmer,
    • S. Sridharan,
    • F. Stagni,
    • V.K. Subbiah,
    • F. Teubert,
    • E. Thomas,
    • D. Tonelli,
    • A. Trisovic,
    • M. Ubeda Garcia,
    • J. Wicht,
    • K. Wyllie,
    • V. Battista,
    • A. Bay,
    • F. Blanc,
    • M. Dorigo,
    • F. Dupertuis,
    • C. Fitzpatrick,
    • S. Gianì,
    • G. Haefeli,
    • P. Jaton,
    • C. Khurewathanakul,
    • I. Komarov,
    • V.N. La Thi,
    • N. Lopez-March,
    • R. Märki,
    • M. Martinelli,
    • B. Muster,
    • T. Nakada,
    • A.D. Nguyen,
    • T.D. Nguyen,
    • C. Nguyen-Mau,
    • J. Prisciandaro,
    • A. Puig Navarro,
    • B. Rakotomiaramanana,
    • J. Rouvinet,
    • O. Schneider,
    • F. Soomro,
    • P. Szczypka,
    • M. Tobin,
    • S. Tourneur,
    • M.T. Tran,
    • G. Veneziano,
    • Z. Xu,
    • J. Anderson,
    • R. Bernet,
    • E. Bowen,
    • A. Bursche,
    • N. Chiapolini,
    • M. Chrzaszcz,
    • Ch. Elsasser,
    • E. Graverini,
    • F. Lionetto,
    • P. Lowdon,
    • K. Müller,
    • N. Serra,
    • O. Steinkamp,
    • B. Storaci,
    • U. Straumann,
    • M. Tresch,
    • A. Vollhardt,
    • R. Aaij,
    • S. Ali,
    • M. van Beuzekom,
    • P.N.Y. David,
    • K. De Bruyn,
    • C. Farinelli,
    • V. Heijne,
    • W. Hulsbergen,
    • E. Jans,
    • P. Koppenburg,
    • A. Kozlinskiy,
    • J. van Leerdam,
    • M. Merk,
    • S. Oggero,
    • A. Pellegrino,
    • H. Snoek,
    • J. van Tilburg,
    • P. Tsopelas,
    • N. Tuning,
    • J.A. de Vries,
    • T. Ketel,
    • R.F. Koopman,
    • R.W. Lambert,
    • D. Martinez Santos,
    • G. Raven,
    • M. Schiller,
    • V. Syropoulos,
    • S. Tolk,
    • A. Dovbnya,
    • S. Kandybei,
    • I. Raniuk,
    • O. Okhrimenko,
    • V. Pugatch,
    • S. Bifani,
    • N. Farley,
    • P. Griffith,
    • I.R. Kenyon,
    • C. Lazzeroni,
    • A. Mazurov,
    • J. McCarthy,
    • L. Pescatore,
    • N.K. Watson,
    • M.P. Williams,
    • M. Adinolfi,
    • J. Benton,
    • N.H. Brook,
    • A. Cook,
    • M. Coombes,
    • J. Dalseno,
    • T. Hampson,
    • S.T. Harnew,
    • P. Naik,
    • E. Price,
    • C. Prouve,
    • J.H. Rademacker,
    • S. Richards,
    • D.M. Saunders,
    • N. Skidmore,
    • D. Souza,
    • J.J. Velthuis,
    • D. Voong,
    • W. Barter,
    • M.-O. Bettler,
    • H.V. Cliff,
    • H.-M. Evans,
    • J. Garra Tico,
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    • G.A. Cowan,
    • S. Eisenhardt,
    • D. Ferguson,
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    • A.-B. Morris,
    • F. Muheim,
    • M. Needham,
    • S. Playfer,
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    • J. Beddow,
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    • L. Eklund,
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    • E. Pesen

Contributions

All authors have contributed to the publication, being variously involved in the design and the construction of the detectors, in writing software, calibrating sub-systems, operating the detectors and acquiring data and finally analysing the processed data.

Competing financial interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to:

Author details

    Extended data figures and tables

    Extended Data Figures

    1. Extended Data Figure 1: Distribution of the dimuon invariant mass mμ+μ in each of the 20 categories. (587 KB)

      Superimposed on the data points in black are the combined fit (solid blue) and its components: the (yellow shaded) and B0 (light-blue shaded) signal components; the combinatorial background (dash-dotted green); the sum of the semi-leptonic backgrounds (dotted salmon); and the peaking backgrounds (dashed violet). The categories are defined by the range of BDT values for LHCb, and for CMS, by centre-of-mass energy, by the region of the detector in which the muons are detected, and by the range of BDT values. Categories for which both muons are detected in the central region of the CMS detector are denoted with CR, those for which at least one muon was detected into the forward region with FR.

    2. Extended Data Figure 2: Distribution of the dimuon invariant mass mμ+μ for the best six categories. (203 KB)

      Categories are ranked according to values of S/(S + B) where S and B are the numbers of signal events expected assuming the SM rates and background events under the peak for a given category, respectively. The mass distribution for the six highest-ranking categories, three per experiment, is shown. Superimposed on the data points in black are the combined full fit (solid blue) and its components: the (yellow shaded) and B0 (light-blue shaded) signal components; the combinatorial background (dash-dotted green); the sum of the semi-leptonic backgrounds (dotted salmon); and the peaking backgrounds (dashed violet).

    3. Extended Data Figure 3: Schematic of the CMS detector and event display for a candidate right arrowμ+μ decay at CMS. (674 KB)

      a, The CMS detector and its components; see ref. 20 for details. b, A candidate decay produced in proton–proton collisions at 8 TeV in 2012 and recorded in the CMS detector. The red arched curves represent the trajectories of the muons from the decay candidate.

    4. Extended Data Figure 4: Schematic of the LHCb detector and event display for a candidate right arrowμ+μ decay at LHCb. (412 KB)

      a, The LHCb detector and its components; see ref. 21 for details. b, A candidate decay produced in proton–proton collisions at 7 TeV in 2011 and recorded in the LHCb detector. The proton–proton collision occurs on the left-hand side, at the origin of the trajectories depicted with the orange curves. The red curves represent the trajectories of the muons from the candidate decay.

    5. Extended Data Figure 5: Confidence level as a function of the (B0right arrowμ+μ) hypothesis. (112 KB)

      The value of 1 − CL, where CL is the confidence level obtained with the Feldman–Cousins procedure, as a function of (B0 right arrow µ+µ) is shown in logarithmic scale. The points mark the computed 1 − CL values and the curve is their spline interpolation. The dark and light (cyan) areas define the two-sided ±1σ and ±2σ confidence intervals for the branching fraction, while the dashed horizontal line defines the confidence level for the 3σ one-sided interval. The dashed (grey) curve shows the 1 − CL values computed from the one-dimensional −2ΔlnL test statistic using Wilks’ theorem. Deviations between these confidence level values and those from the Feldman–Cousins procedure30 illustrate the degree of approximation implied by the asymptotic assumptions inherent to Wilks’ theorem29.

    6. Extended Data Figure 6: Likelihood contours for the ratios of the branching fractions with respect to their SM prediction, in the versus plane. (286 KB)

      a, The (black) cross marks the central value returned by the fit. The SM point is shown as the (red) square located, by construction, at . Each contour encloses a region approximately corresponding to the reported confidence level. The SM branching fractions are assumed uncorrelated to each other, and their uncertainties are accounted for in the likelihood contours. b, c, Variations of the test statistic 2ΔlnL for and are shown in b and c, respectively. The SM is represented by the (red) vertical lines. The dark and light (cyan) areas define the ±1σ and ±2σ confidence intervals, respectively.

    7. Extended Data Figure 7: Search for the right arrowμ+μ and B0right arrowμ+μdecays, reported by 11 experiments spanning more than three decades, and by the present results. (235 KB)

      Markers without error bars denote upper limits on the branching fractions at 90% confidence level, while measurements are denoted with error bars delimiting 68% confidence intervals. The solid horizontal lines represent the SM predictions for the and B0 right arrow µ+µ branching fractions1; the blue (red) lines and markers relate to the (B0 right arrow µ+µ) decay. Data (see key) are from refs 17, 18, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60; for details see Methods. Inset, magnified view of the last period in time.

    Additional data