KM3NeT Constraint on Lorentz-Violating Superluminal Neutrino Velocity

TL;DR

This paper uses the highest energy neutrino detection to set the most stringent constraints on superluminal neutrino velocities, testing Lorentz invariance at unprecedented energy scales.

Contribution

It provides a novel, highly sensitive neutrino-based test of Lorentz invariance using the highest energy neutrino observed to date.

Findings

Sets a new upper limit on superluminal neutrino velocity at δ < 4×10^{-22}

Uses the highest energy neutrino detection to test fundamental physics

Strengthens constraints on Lorentz-violating theories

Abstract

Lorentz invariance is a fundamental symmetry of spacetime and foundational to modern physics. One of its most important consequences is the constancy of the speed of light. This invariance, together with the geometry of spacetime, implies that no particle can move faster than the speed of light. In this article, we present the most stringent neutrino-based test of this prediction, using the highest energy neutrino ever detected to date, KM3-230213A. The arrival of this event, with an energy of $220^{+570}_{-110}\,\text{PeV}$, sets a constraint on $\delta \equiv c_\nu^2-1 < 4\times10^{-22}$.