A method of eta' decay product selection to study partial chiral symmetry restoration

TL;DR

This paper proposes a kinematic method to identify pions from eta' decays, aiming to study partial chiral symmetry restoration by analyzing changes in two-pion correlations in high-energy collisions.

Contribution

A novel kinematic selection technique for eta' decay pions, applicable across various collision systems and energies, to investigate chiral symmetry restoration effects.

Findings

Method effectively selects eta' decay pions in simulations.

Selection improves sensitivity to eta' mass decrease signals.

Applicable to multiple collision systems and energies.

Abstract

In case of chiral U_A(1) symmetry restoration the mass of the eta' boson (the ninth, would-be Goldstone boson) is decreased, thus its production cross section is heavily enhanced. The eta' decays (through one of its decay channels) into five pions. These pions will not be correlated in terms of Bose-Einsten correlations, thus the production enhancement changes the strength of two-pion correlation functions at low momentum. Preliminary results strongly support the mass decrease of the eta' boson. In this paper we propose a method to select pions coming from eta' decays. We investigate the efficiency of the proposed kinematical cut in several collision systems and energies with several simulators. We prove that our method can be used in all investigeted collision systems.