Cumulants of conserved charges in hydrodynamic simulations

TL;DR

This paper presents a fast, straightforward method to compute cumulants of conserved charge fluctuations in hydrodynamic simulations, incorporating conservation law corrections, and validates it against experimental data from heavy-ion collisions.

Contribution

The paper introduces a novel, efficient approach to calculate cumulants in hydrodynamic models, accounting for conservation laws, and demonstrates its accuracy with experimental data.

Findings

Method accurately reproduces experimental fluctuation data.

Incorporating conservation laws improves cumulant calculations.

Approach is computationally efficient for event-by-event simulations.

Abstract

We introduce a fast and simple method of computing cumulants of net-proton or net-charge fluctuations in event-by-event hydrodynamic simulations of heavy-ion collisions. One evaluates the mean numbers of particles in every hydrodynamic event. Cumulants are then expressed as a function of these mean numbers. We implement the corrections due to global conservation laws. The method is tested using ideal hydrodynamic simulations of Au+Au collisions at $\sqrt{s_{NN}}=200$ AGeV with the NeXSPheRIO code. Results are in good agreement with experimental data on net-proton and net-charge fluctuations by the STAR collaboration.