Production of Light Nuclei in Au+Au Collisions with the STAR BES-II Program

TL;DR

This paper reports on measurements of light nuclei production in Au+Au collisions at BES-II energies, providing insights into the underlying particle production mechanisms and potential signals of critical phenomena in the QCD phase diagram.

Contribution

It presents new, more precise measurements of light nuclei yields, ratios, and coalescence parameters across various energies and centralities, utilizing the enhanced capabilities of STAR BES-II.

Findings

Yields and ratios of light nuclei vary with collision energy and centrality.

Light nuclei to proton yield ratios and coalescence parameters are quantified.

Results support the use of these observables as probes for critical phenomena.

Abstract

The yields and ratios of light nuclei in heavy-ion collisions offer a method to distinguish between the thermal and coalescence models. Ratios such as $\rm N_t \times N_p/N_d^2$ and $\rm N_{^3He} \times N_p/N_d^2$ are suggested as potential probes to investigate critical phenomena within the QCD phase diagram. The significantly larger datasets from STAR BES-II compared to BES-I, combined with enhanced detector capabilities, allow for more precise measurements. In this proceeding, we present the centrality and energy dependence of transverse momentum spectra and particle yields of (anti-)proton, (anti-)deuteron, and $\rm ^3He$ at BES-II energies ($\sqrt{s_{\rm NN}}$ = $7.7 - 27$ GeV), as well as the light nuclei to proton yield ratios and coalescence parameters $(B_2(\rm d)$ and $B_3(\rm ^3He))$.