Modifications of Heavy-Flavor Spectra in $\sqrt{s_{\rm NN}}=62.4~{\rm GeV}$ Au-Au Collisions

TL;DR

This paper models heavy-flavor particle production in gold-gold collisions at 62.4 GeV, revealing how medium interactions and initial effects influence particle suppression and flow, especially at lower energies where medium coupling is strongest.

Contribution

It applies a nonperturbative transport approach to lower-energy collisions, highlighting the impact of medium coupling and initial-state effects on heavy-flavor observables.

Findings

Suppression and flow of heavy-flavor decay electrons are influenced by thermalization and initial-state effects.

Cronin enhancement becomes more significant at lower collision energies.

Medium coupling effects are strongest in the pseudo-critical region, affecting particle spectra.

Abstract

We calculate open heavy-flavor (HF) production in Au+Au collisions at $\sqrt{s_{\rm NN}}$=62.4 GeV utilizing a nonperturbative transport approach as previously applied in nuclear collisions at top RHIC and LHC energies. The effects of hot QCD matter are treated in a strong-coupling framework, by implementing heavy-quark diffusion, hadronization and heavy-flavor meson diffusion within a hydrodynamic background evolution. Since in our approach the heavy-flavor coupling to the medium is strongest in the pseudo-critical region, it is of interest to test its consequences at lower collision energies where the sensitivity to this region should be enhanced relative to the hotter (early) fireball temperatures reached at top RHIC and LHC energies. We find that the suppression and flow pattern of the non-photonic electrons from heavy-flavor decays at 62.4 GeV emerges from an intricate interplay of thermalization and initial-state effects, in particular a Cronin enhancement which is known to become more pronounced toward lower collision energies.