Baryon clustering at the critical line and near the hypothetical critical point in heavy-ion collisions

TL;DR

This paper investigates baryon clustering near the QCD critical point in heavy-ion collisions, analyzing how critical fluctuations influence nucleon clustering and their observable signatures in experimental data.

Contribution

It introduces a model linking critical mode fluctuations to baryon clustering, providing insights into cluster formation near the QCD critical point in heavy-ion collisions.

Findings

Clustering of nucleons increases near the critical point.

Higher-order moments of baryon distributions show critical behavior.

Finite-time effects influence cluster formation in realistic collisions.

Abstract

We study clustering of baryons at the freeze-out point of relativistic heavy-ion collisions. Using a Walecka-Serot model for the nucleon-nucleon (NN) interaction we analyze how the modified/critical $\sigma$ mode---responsible for the NN attraction---allows for clustering of nucleons when the system is close to a possible critical point of QCD. We investigate clusters of few nucleons, and also the internal cluster configuration when the system is long lived. For realistic heavy-ion collisions we study to how extend such clusters can be formed in a finite time, and perform the statistical analysis of cumulants and higher-order moments (skewness and kurtosis) for collisions at the Beam Energy Scan of RHIC.