Neutrinos interact only very weakly, so they are extremely penetrating. The theoretical neutrino–nucleon interaction cross-section, however, increases with increasing neutrino energy, and neutrinos with energies above 40 teraelectronvolts (TeV) are expected to be absorbed as they pass through the Earth. Experimentally, the cross-section has been determined only at the relatively low energies (below 0.4 TeV) that are available at neutrino beams from accelerators1,2. Here we report a measurement of neutrino absorption by the Earth using a sample of 10,784 energetic upward-going neutrino-induced muons. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the neutrino–nucleon interaction cross-section for neutrino energies 6.3–980 TeV, more than an order of magnitude higher than previous measurements. The measured cross-section is about 1.3 times the prediction of the standard model3, consistent with the expectations for charged- and neutral-current interactions. We do not observe a large increase in the cross-section with neutrino energy, in contrast with the predictions of some theoretical models, including those invoking more compact spatial dimensions4 or the production of leptoquarks5. This cross-section measurement can be used to set limits on the existence of some hypothesized beyond-standard-model particles, including leptoquarks.
We acknowledge support from the following agencies: United States Air Force Academy, US National Science Foundation, Office of Polar Programs; US National Science Foundation, Physics Division; University of Wisconsin Alumni Research Foundation; the Grid Laboratory of Wisconsin (GLOW) grid infrastructure at the University of Wisconsin, Madison; the Open Science Grid (OSG) grid infrastructure; US Department of Energy; National Energy Research Scientific Computing Center; the Louisiana Optical Network Initiative (LONI) grid computing resources; Natural Sciences and Engineering Research Council of Canada; WestGrid and Compute/Calcul Canada; Swedish Research Council; Swedish Polar Research Secretariat; Swedish National Infrastructure for Computing (SNIC); Knut and Alice Wallenberg Foundation; German Ministry for Education and Research (BMBF); Deutsche Forschungsgemeinschaft (DFG); Helmholtz Alliance for Astroparticle Physics (HAP); Initiative and Networking Fund of the Helmholtz Association, Germany; Fund for Scientific Research (FNRS-FWO), FWO Odysseus programme, Flanders Institute to encourage scientific and technological research in industry (IWT), Belgian Federal Science Policy Office (BELSPO); Marsden Fund; Australian Research Council; Japan Society for Promotion of Science (JSPS); Swiss National Science Foundation (SNSF); National Research Foundation of Korea (NRF); Villum Fonden, Danish National Research Foundation (DNRF).