FIGURE 2. The Higgs boson at the LHC.

A Higgs (H) boson may be produced by a range of interactions, two examples of which are shown here. The first, a, is through fusion of gluons (g) from the protons in the LHC beams, through a top (t) quark loop; and the second, b, is through a bremsstrahlung process, in which a quark (q) and antiquark annihilate to create a W or Z boson, which may then radiate a Higgs. c, The Higgs itself then decays, and it is these decay products that will be caught in a detector. The 'branching fraction' or probability of decay to certain products depends on the (as-yet unknown) mass of the Higgs particle, which is dominated by decay to a bottom–antibottom quark pair at low mass, but by decay to pairs of W bosons at high mass.