High-energy neutrino interaction physics with IceCube

TL;DR

IceCube analyzes high-energy neutrino interactions, measuring cross-sections and inelasticity at energies up to 980 TeV, providing tests of the Standard Model and insights into astrophysical neutrino fluxes.

Contribution

First measurements of neutrino-nucleon cross-section and inelasticity at energies above 1 TeV using IceCube data, extending knowledge beyond accelerator capabilities.

Findings

Neutrino-nucleon cross-section is 1.30 times the Standard Model prediction.

Inelasticity measurements agree with Standard Model expectations.

Constraints on astrophysical neutrino flux and flavor ratios.

Abstract

Although they are best known for studying astrophysical neutrinos, neutrino telescopes like IceCube can study neutrino interactions, at energies far above those that are accessible at accelerators. In this writeup, I present two IceCube analyses of neutrino interactions at energies far above 1 TeV. The first measures neutrino absorption in the Earth, and, from that determines the neutrino-nucleon cross-section at energies between 6.3 and 980 TeV. We find that the cross-sections is 1.30 $^{+0.21}_{-0.19}$ (stat.) $^{+0.39}_{-0.43}$ (syst.) times the Standard Model cross-section. We also present a measurement of neutrino inelasticity, using $\nu_\mu$ charged-current interactions that occur within IceCube. We have measured the average inelasticity at energies from 1 TeV to above 100 TeV, and found that it is in agreement with the Standard Model expectations. We have also performed a series of fits to this track sample and a matching cascade sample, to probe aspects of the astrophysical neutrino flux, particularly the flavor ratio.