STAR measurement of system size and incident energy dependence of pt correlations at RHIC

TL;DR

This paper investigates how event-by-event transverse momentum fluctuations and correlations vary with system size and incident energy in heavy-ion collisions at RHIC, revealing energy and size independence in scaled correlations.

Contribution

It provides the first detailed comparison of pt fluctuations and correlations across different system sizes and energies at RHIC, highlighting their dependence on collision centrality.

Findings

Dynamical pt fluctuations decrease with collision centrality.

Pt correlations decrease from peripheral to central collisions.

Scaled pt correlations are independent of beam energy and system size.

Abstract

We present the results on measurement of event-by-event pt fluctuations and correlations for Cu+Cu collisions at sqrt{sNN} = 62.4 and 200 GeV from STAR experiment at RHIC. These results are compared with those from Au+Au collisions at sqrt{sNN} = 62.4 and 200 GeV to study the system size dependence. We find that the dynamical pt fluctuations are finite and decrease with increasing collision centrality. The pt correlations are studied as a function of collision centrality and are observed to decrease as we go from peripheral to central collisions. The square root of pt correlations scaled by mean pt are observed to be independent of beam energy as well as colliding ion size.