Investigation of Experimental Observables in Search of the Chiral Magnetic Effect in Heavy-ion Collisions in the STAR experiment

TL;DR

This paper investigates experimental observables for detecting the chiral magnetic effect in heavy-ion collisions, comparing methods using simulations and event generators to evaluate their sensitivity and consistency.

Contribution

It introduces a comparative analysis of three experimental approaches for CME detection, verifying their equivalence and sensitivity using simulations and realistic event generators.

Findings

The three observables are equivalent in their kernel components.

Simulations show consistent sensitivity to the CME signal.

Results inform optimal strategies for CME detection in heavy-ion collisions.

Abstract

The chiral magnetic effect (CME) is a novel transport phenomenon, arising from the interplay between quantum anomalies and strong magnetic fields in chiral systems. In high-energy nuclear collisions, the CME may survive the expansion of the quark-gluon plasma fireball and be detected in experiments. Over the past decade, the experimental searches for the CME have aroused extensive interest at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). The main goal of this article is to investigate three pertinent experimental approaches: the $\gamma$ correlator, the $R$ correlator and the signed balance functions. We will exploit both simple Monte Carlo simulations and a realistic event generator (EBE-AVFD) to verify the equivalence in the kernel-component observables among these methods and to ascertain their sensitivities to the CME signal for the isobaric collisions at RHIC.