Probe for the strong parity violation effects at RHIC with three particle correlations

TL;DR

This paper investigates potential strong parity violation effects in heavy ion collisions at RHIC by analyzing three-particle azimuthal correlations, aiming to detect charge separation phenomena possibly caused by P-odd domains.

Contribution

It applies a specific three-particle correlation observable to experimental data from RHIC to search for signs of strong parity violation in heavy ion collisions.

Findings

No definitive evidence of strong parity violation detected.

Results depend on collision centrality, rapidity separation, and transverse momentum.

Discusses possible non-parity-related contributions to the observed correlations.

Abstract

In non-central relativistic heavy ion collisions, \P-odd domains, which might be created in the process of the collision, are predicted to lead to charge separation along the system orbital momentum \cite{Kharzeev:2004ey}. An observable, \P-even, but directly sensitive to the charge separation effect, has been proposed in \cite{Voloshin:2004vk} and is based on 3-particle mixed harmonics azimuthal correlations. We report the STAR measurements using this observable for Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}$=200 and 62 GeV. The results are reported as function of collision centrality, particle separation in rapidity, and particle transverse momentum. Effects that are not related to parity violation but might contribute to the signal are discussed.