Charm-strange meson production in ultra-relativistic heavy-ion collisions at the CERN-LHC energies

Abstract

The nuclear modification factor $R_{\mathrm{AA}}$ and the elliptic flow coefficient $v_2$ of charm-strange meson $D_s^{+}$ is systematically studied in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02\mathrm{TeV}$ and $2.76\mathrm{TeV}$. During the modeling, the coupling strength between the injected charm quark and the incident medium constituents, is extracted from the lattice QCD calculations: $2\pi T{D}_s=7$ (\textbf{Model-A}) and $2\pi T{D}_s=1.3+(T/T_c{)}^2$ (\textbf{Model-B}). We find that, comparing $R_{\mathrm{AA}}(D_s^{+})$ with $R_{\mathrm{AA}}(non-strange)$, the heavy-light coalescence effect is more pronounced for the former one, resulting in an enhancement behavior in the range $2\lesssim p_{\mathrm{T}}\lesssim 5\mathrm{GeV}$. The predictions of $R_{\mathrm{AA}}(D_s^{+})$ and $R_{\mathrm{AA}}(non-strange)$ favor Model-A to have a better description of the measured $p_{\mathrm{T}}$ dependence in both energies, while their $v_2$ prefer Model-B at moderate $p_{\mathrm{T}}$ ($2\lesssim p_{\mathrm{T}}\lesssim 4\mathrm{GeV}$). Therefore, it is necessary to consider the temperature- and/or momentum-dependence of $2\pi T{D}_s$ to describe simultaneously $R_{\mathrm{AA}}(D_s^{+})$ and $v_2(D_s^{+})$ in different centrality classes in Pb--Pb collisions.

Comments: 8 pages, 8 figures; Accepted by Phys. Rev. C