Modified energy-momentum conservation laws and vacuum Cherenkov radiation

TL;DR

This paper develops a framework for Lorentz-violating kinematics with modified energy-momentum conservation laws, analyzing their effects on decay thresholds and setting bounds from vacuum Cherenkov radiation observations.

Contribution

It introduces a general parametrization including modified conservation laws beyond effective field theory, and applies it to derive bounds from vacuum Cherenkov radiation data.

Findings

Bounds on Lorentz violation from Cherenkov radiation non-observation

Modified conservation laws impact decay thresholds

Comparison with effective field theory results

Abstract

We present a general parametrization for the leading order terms in a momentum power expansion of a non-universal Lorentz-violating, but rotational invariant, kinematics and its implications for two-body decay thresholds. The considered framework includes not only modified dispersion relations for particles, but also modified energy-momentum conservation laws, something which goes beyond effective field theory. As a particular and relevant example, bounds on the departures from special relativistic kinematics from the non-observation of vacuum Cherenkov radiation are discussed and compared with those obtained within the effective field theory scenario.