Noncommutativity and Lorentz Violation in Relativistic Heavy Ion Collisions

TL;DR

This paper explores how intense magnetic fields in relativistic heavy ion collisions could reveal effects of noncommutative geometry and Lorentz violation, potentially tightening bounds on noncommutativity parameters.

Contribution

It proposes using lepton pair production signatures in heavy ion collisions to set more stringent bounds on noncommutativity and Lorentz violation effects.

Findings

Intense magnetic fields in heavy ion collisions may produce detectable noncommutative effects.

Non-observation of exotic events could improve bounds on noncommutativity parameter .

The study suggests a new experimental approach to test fundamental physics theories.

Abstract

The experimental detection of the effects of noncommuting coordinates in electrodynamic phenomena depends on the magnitude of |\theta B|, where \theta is the noncommutativity parameter and B a background magnetic field. With the present upper bound on \theta, given by \theta_{\rm bound} \simeq 1/(10 {\rm TeV})^2, there was no large enough magnetic field in nature, including those observed in magnetars, that could give visible effects or, conversely, that could be used to further improve \theta_{\rm bound}. On the other hand, recently it has been proposed that intense enough magnetic fields should be produced at the beginning of relativistic heavy ion collisions. We discuss here lepton pair production by free photons as one kind of signature of noncommutativity and Lorentz violation that could occur at RHIC or LHC. This allows us to obtain a more stringent bound on \theta, given by 10^{-3} \theta_{\rm bound}, if such "exotic" events do not occur.