Bounding Isotropic Lorentz Violation Using Synchrotron Losses at LEP

TL;DR

This paper uses precise measurements of synchrotron radiation at LEP to set stringent laboratory bounds on isotropic Lorentz violation, improving constraints on deviations from special relativity.

Contribution

It provides a new laboratory-based constraint on isotropic Lorentz violation using LEP synchrotron loss data, complementing astrophysical bounds.

Findings

Isotropic Lorentz violation parameter constrained to less than 5 x 10^(-15)

Laboratory measurements can effectively test fundamental physics deviations

Results improve existing bounds on Lorentz symmetry violations

Abstract

Some deviations from special relativity--especially isotropic effects--are most efficiently constrained using particles with velocities very close to 1. While there are extremely tight bounds on some of the relevant parameters coming from astrophysical observations, many of these rely on our having an accurate understanding of the dynamics of high-energy sources. It is desirable to have reliable laboratory constraints on these same parameters. The fastest-moving particles in a laboratory were electrons and positrons at LEP. The energetics of the LEP beams were extremely well understood, and measurements of the synchrotron emission rate indicate that that any isotropic deviation of the speed of light from 1 must be smaller than 5 x 10^(-15).