Baryon Clustering at the critical line and near the hypothetical critical point

Abstract

We study clustering of baryons at the freeze-out point of relativistic heavy-ion collisions, see [E. Shuryak and J.M. Torres-Rincon, arXiv:1805.04444 [hep-ph]]. Using a Walecka-Serot model for the nucleon-nucleon (NN) interaction we analyze how the modified/critical σ 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 large cluster configurations 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. We finally suggest usage of out-of-equilibrium production of light nuclei d, t, He3, He4 and provide estimates for their formation in such collisions due to clustering.