Testing the Chiral Magnetic Effect with Central U+U collisions

TL;DR

This paper discusses testing the chiral magnetic effect (CME) in heavy-ion collisions, proposing specific collision configurations to distinguish CME signals from background effects, aiming to clarify experimental observations.

Contribution

It introduces the use of central body-body U+U collisions to separate CME signals from background correlations, enhancing the interpretability of experimental data.

Findings

Charge-dependent correlations are consistent with CME but may include background effects.

Proposes using specific collision geometries to disentangle CME signals.

Suggests further studies with isobaric beam collisions.

Abstract

A quark interaction with topologically nontrivial gluonic fields, instantons and sphalerons, violates \P~ and \CP~ symmetry. In the strong magnetic field of a noncentral nuclear collision such interactions lead to the charge separation along the magnetic field, the so-called chiral magnetic effect (CME). Recent results from the STAR collaboration on charge dependent correlations are consistent with theoretical expectations for CME but may have contributions from other effects, which prevents definitive interpretation of the data. Here I propose to use central body-body $U+U$ collisions to disentangle correlations due to CME from possible background correlations due to elliptic flow. Further more quantitative studies can be performed with collision of isobaric beams.