Critical Point Fluctuations in Heavy-Ion Collisions within Molecular Dynamics with Expansion

¹ Physics Department, University of Houston, 3507 Cullen Blvd, Houston, TX 77204, USA
² Nuclear Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
³ Department of the high-density Energy Physics, Bogolyubov Institute for Theoretical Physics, 03680 Kyiv, Ukraine

^* e-mail: vkuzniet@cougarnet.uh.edu

Published online: 27 January 2025

Abstract

We analyze particle number fluctuations near the critical endpoint of a first-order phase transition using molecular dynamics simulations of the Lennard-Jones fluid. Building on our previous study [V.A. Kuznietsov et al., Phys. Rev. C 105, 044903 (2022)], we incorporate longitudinal collective flow. The scaled variance of particle number distributions in various coordinate and momentum space acceptances is computed through ensemble averaging, confirming previous time-averaging results. We find that significant collective flow is crucial for observing large fluctuations from the critical point in momentum space. These results are discussed in the context of heavy-ion collisions.