Azimuthal charged particle correlations as a probe for local strong parity violation in heavy-ion collisions

TL;DR

This paper investigates local strong parity violation in heavy-ion collisions by measuring charge separation using three-particle azimuthal correlations, analyzing background effects, and comparing results across different collision systems and energies.

Contribution

It provides experimental evidence of charge separation indicative of local parity violation and assesses background contributions using event generators.

Findings

Observation of charge separation consistent with local parity violation

Quantitative analysis of background effects on measured correlations

Comparison of results across different collision energies and systems

Abstract

One of the most interesting and important phenomena predicted to occur in heavy-ion collisions is the local strong parity violation. In non-central collisions, it is expected to result in charge separation of produced particles along the system's orbital momentum. I report on results of the charge separation measurement in Au+Au and Cu+Cu collisions at sqrt(s_NN)= 200 and 62 GeV with the STAR detector at RHIC based on three-particle mixed harmonic azimuthal correlations. Systematic study of parity conserving (background) effects with existing heavy-ion event generators, and their possible contributions to the observed correlations are also present.