Pion Interferometry in Au+Au and Cu+Cu Collisions at $\sqrt{s_{\rm{NN}}}$ = 62.4 and 200 GeV

TL;DR

This paper analyzes two-pion interferometry in Au+Au and Cu+Cu collisions at RHIC energies, revealing that the correlation radii scale with multiplicity regardless of system size or collision energy.

Contribution

It provides a systematic study of pion correlation lengths and their scaling with multiplicity across different collision systems and energies at RHIC.

Findings

Correlation radii depend on multiplicity and transverse momentum.

Scaling of system volume with multiplicity is consistent across systems.

Correlation radii are independent of collision energy and system size.

Abstract

We present a systematic analysis of two-pion interferometry in Au+Au collisions at $\sqrt{s_{\rm{NN}}}$ = 62.4 GeV and Cu+Cu collisions at $\sqrt{s_{\rm{NN}}}$ = 62.4 and 200 GeV using the STAR detector at RHIC. The multiplicity and transverse momentum dependences of the extracted correlation lengths (radii) are studied. The scaling with charged particle multiplicity of the apparent system volume at final interaction is studied for the RHIC energy domain. The multiplicity scaling of the measured correlation radii is found to be independent of colliding system and collision energy.