Beam Energy dependence of Light Nuclei Production in Au+Au Collisions

TL;DR

This study models the production of light nuclei in gold-gold collisions across various energies, predicting monotonic trends that serve as a baseline for detecting QCD critical points, but it does not reproduce the observed non-monotonic experimental behavior.

Contribution

The paper introduces a new hybrid dynamical model to predict light nuclei yields across collision energies without including QCD critical point effects.

Findings

Coalescence parameters decrease monotonically with energy

Light nuclei yield ratios remain approximately constant

Model predictions do not match the non-monotonic experimental data

Abstract

We study the collision energy dependence of (anti-)deuteron and (anti-)triton production in the most central Au+Au collisions at $\sqrt{s_\mathrm{NN}}=$ 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV, using the nucleon coalescence model. The needed phase-space distribution of nucleons at the kinetic freeze-out is generated from a new 3D hybrid dynamical model (\texttt{iEBE-MUSIC}) by using a smooth crossover equation of state (EoS) without a QCD critical point. Our model calculations predict that the coalescence parameters of (anti-)deuteron ($B_2(d)$ and $B_2(\bar{d})$) decrease monotonically as the collision energy increases, and the light nuclei yield ratio $N_t N_p/N_d^2$ remains approximately a constant with respect to the collision energy. These calculated observables fail to reproduce the non-monotonic behavior of the corresponding data from the STAR Collaboration. Without including any effects of the critical point in our model, our results serve as the baseline predictions for the yields of light nuclei in the search for the possible QCD critical points from the experimental beam energy scan of heavy ion collisions.