Transverse Momentum Fluctuations and Correlations

TL;DR

This paper investigates transverse momentum fluctuations and correlations in heavy-ion collisions, linking them to initial source fluctuations and collective flow, supported by hydrodynamic modeling.

Contribution

It introduces a new observable for transverse momentum correlations that directly relates to collective flow variables, enhancing analysis of collision dynamics.

Findings

Hydrodynamic models with quark degrees of freedom reproduce experimental data.

Event-by-event fluctuations relate to initial source size and entropy.

Proposed observable effectively captures correlations of collective flow.

Abstract

We study fluctuations and correlations of the average transverse momentum of particles emitted in heavy-ion collisions. Fluctuations of the average transverse momentum are related to event-by-event fluctuations of the size and entropy of the initial source. Hydrodynamic calculations using a Glauber model with quark degrees of freedom reproduce the data. We study correlations of the average transverse momentum in different rapidity bins. We propose a definition of the observable that can be directly related to correlations of the collective flow variables.