Search for a Lorentz-violating sidereal signal with atmospheric neutrinos in IceCube

TL;DR

This study used IceCube atmospheric neutrino data to search for sidereal signals indicating Lorentz violation, finding no such signals but significantly improving constraints on Lorentz-violating parameters.

Contribution

It introduces a novel analysis of atmospheric neutrino data to set new, tighter limits on Lorentz and CPT violation in neutrino oscillations.

Findings

No sidereal modulation detected in neutrino flux.

Constraints on Lorentz-violating coefficients improved by up to three orders of magnitude.

Demonstrated IceCube's high-energy reach enhances sensitivity to fundamental physics.

Abstract

A search for sidereal modulation in the flux of atmospheric muon neutrinos in IceCube was performed. Such a signal could be an indication of Lorentz-violating physics. Neutrino oscillation models, derivable from extensions to the Standard Model, allow for neutrino oscillations that depend on the neutrino's direction of propagation. No such direction-dependent variation was found. A discrete Fourier transform method was used to constrain the Lorentz and CPT-violating coefficients in one of these models. Due to the unique high energy reach of IceCube, it was possible to improve constraints on certain Lorentz-violating oscillations by three orders of magnitude with respect to limits set by other experiments.