Limits on neutrino Lorentz violation from multimessenger observations of TXS 0506+056

Abstract

The observation by the IceCube Collaboration of a high-energy (E≳200 TeV) neutrino from the direction of the blazar TXS 0506+056 and the coincident observations of enhanced γ-ray emissions from the same object by MAGIC and other experiments can be used to set stringent constraints on Lorentz violation in the propagation of neutrinos that is linear in the neutrino energy: Δv=−E/M1, where Δv is the deviation from the velocity of light, and M1 is an unknown high energy scale to be constrained by experiment. Allowing for a difference in neutrino and photon propagation times of ∼10 days, we find that M1≳3×1016 GeV. This improves on previous limits on linear Lorentz violation in neutrino propagation by many orders of magnitude, and the same is true for quadratic Lorentz violation. Keywords: Lorentz violation, Multimessenger, Astrophysical neutrinos, Blazar, TXS 0506+056, IceCube