Observation of $D_{s}^{\pm}/D^0$ enhancement in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}$ = 200 GeV

TL;DR

This study reports the first measurement of $D_s^{ m iny ootnotesize ext{±}}$ meson production in Au+Au collisions at 200 GeV, revealing a significant enhancement over $p$+$p$ collisions and supporting coalescence hadronization in the quark-gluon plasma.

Contribution

It provides the first experimental evidence of $D_s^{ m iny ootnotesize ext{±}}$ enhancement in heavy-ion collisions and compares it with model predictions, highlighting the role of strange-quark coalescence.

Findings

Significant $D_s^{ m iny ootnotesize ext{±}}$ enhancement observed in Au+Au collisions.

Model calculations with QGP strange-quark production qualitatively reproduce the data.

Yield ratios are consistent with statistical hadronization model predictions.

Abstract

We report on the first measurement of charm-strange meson $D_s^{\pm}$ production at midrapidity in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}$ = 200 GeV from the STAR experiment. The yield ratio between strange ($D_{s}^{\pm}$) and non-strange ($D^{0}$) open-charm mesons is presented and compared to model calculations. A significant enhancement, relative to a PYTHIA simulation of $p$+$p$ collisions, is observed in the $D_{s}^{\pm}/D^0$ yield ratio in Au+Au collisions over a large range of collision centralities. Model calculations incorporating abundant strange-quark production in the quark-gluon plasma (QGP) and coalescence hadronization qualitatively reproduce the data. The transverse-momentum integrated yield ratio of $D_{s}^{\pm}/D^0$ at midrapidity is consistent with a prediction from a statistical hadronization model with the parameters constrained by the yields of light and strange hadrons measured at the same collision energy. These results suggest that the coalescence of charm quarks with strange quarks in the QGP plays an important role in $D_{s}^{\pm}$ meson production in heavy-ion collisions.