Light Nuclei Production in Au+Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5-200 GeV from JAM model

TL;DR

This study uses the JAM transport model to analyze light nuclei production in central Au+Au collisions across a wide energy range, revealing limitations in current models to reproduce observed neutron density fluctuation signals related to the QCD critical point.

Contribution

It provides a systematic energy-dependent analysis of light nuclei yields using the JAM model, highlighting discrepancies with experimental non-monotonic trends in neutron fluctuation indicators.

Findings

Yield ratios are flat across energies, inconsistent with STAR's non-monotonic observations.

The model cannot reproduce the neutron density fluctuation signals linked to the QCD critical point.

Provides constraints for future searches of the QCD critical point using light nuclei production.

Abstract

Light nuclei production is sensitive to the baryon density fluctuations and can be used to probe the QCD phase transition in relativistic heavy-ion collisions. In this work, we studied the production of proton, deuteron, triton in central Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5, 7.7, 11.5, 14.5, 19.6, 27, 39, 54.4, 62.4 and 200 GeV from a transport model (JAM). Based on the coalescence production of light nuclei, we calculated the energy dependence of rapidity density $dN/dy$ and particle ratios ($d/p$, $t/p$, and $t/d$). More importantly, the yield ratio $N_{{t}} \times N_{{p}} / N_{{d}}^{2}$, which is sensitive to the neutron density fluctuations, shows a flat energy dependence and cannot describe the non-monotonic trend observed by the STAR experiment. Based on the nucleon coalescence, this work can provide constraint and reference to search for the QCD critical point and/or first order phase transition with light nuclei production in future heavy-ion collision experiments.