$\mathbf{D_s}$-Meson as Quantitative Probe of Diffusion and Hadronization in Nuclear Collisions

TL;DR

This paper uses $D_s$-mesons as a quantitative probe to study diffusion and hadronization processes in the hot nuclear medium created in ultrarelativistic heavy-ion collisions, highlighting the role of strangeness enhancement and collective flow.

Contribution

It introduces a consistent strong-coupling approach combining hydrodynamics and nonperturbative interactions to predict $D_s$-meson spectra modifications and their sensitivity to medium properties.

Findings

Predicted a large enhancement of $D_s$ $R_{AA}$ at RHIC.

Identified the maximum $R_{AA}$ of 1.5-1.8 at around 2 GeV/$c$.

Suggested diffusion effects in the hadronic phase can distinguish transport properties.

Abstract

The modifications of $D_s$-meson spectra in ultrarelativistic heavy-ion collisions are identified as a quantitative probe of key properties of the hot nuclear medium. This is enabled by the unique valence-quark content of the $D_s$=$c\bar{s}$ which couples the well-known strangeness enhancement with the collective-flow pattern of primordially produced charm quarks. We employ a consistent strong-coupling treatment with hydrodynamic bulk evolution and nonperturbative $T$-matrix interactions for both heavy-quark diffusion and hadronization in the Quark-Gluon Plasma (QGP). A large enhancement of the $D_s$ nuclear modification factor ($R_{AA}$) at RHIC is predicted, with a remarkable maximum of $\sim$1.5-1.8 at transverse momenta around 2 GeV/$c$. We show this to be a direct consequence of the strong coupling of the heavy quarks to the QGP and their hadronization via coalescence with strange quarks. We furthermore introduce the effects of diffusion in the hadronic phase and suggest that an increase of the $D$-meson elliptic flow compared to the $D_s$ can disentangle the transport properties of hadronic and QGP liquids.