Production of open-charm mesons in relativistic heavy-ion collisions

Abstract

We present a theoretical framework to study open charm production in relativistic heavy-ion collisions. The coupling strength between the charm quarks and the QGP constituents, quantified by the spatial diffusion coefficient $2\pi T{D}_s$, is obtained by performing a phenomenological fit analysis to the lattice QCD calculations, resulting in $2\pi T{D}_s=const.$ (\textbf{Model-A}) and $2\pi T{D}_s=1.3+(T/T_c{)}^2$ (\textbf{Model-B}). We find that the relative azimuthal distribution of the initially back-to-back generated $c\bar{c}$ pairs presents a broadening behaviour, which is more pronounced for $c\bar{c}$ pairs with small initial $p_{\mathrm{T}}$, and when the Model-B approach is adopted. The competition between the initial drag and the subsequent collective effects tends to restrict the time dependence of charm quark $R_{\mathrm{AA}}$. Concerning the theoretical uncertainty on final D-meson nuclear modification, the nuclear shadowing and pp baseline components are dominat at high and low $p_{\mathrm{T}}$ ($p_{\mathrm{T}}\lesssim 3GeV/c$), respectively. The measured D-meson $R_{\mathrm{AA}}(p_{\mathrm{T}})$ favors Model-A assumption for the diffusion coefficient both at RHIC and LHC, while their $v_2(p_{\mathrm{T}})$ prefer Model-B at moderate $p_{\mathrm{T}}$. These results confirm the necessity to consider the temperature- and/or momentum-dependence of $2\pi T{D}_s$ to describe well the D-meson $R_{\mathrm{AA}}$ and $v_2$ simultaneously.

Comments: 17 pages, 18 figures; Accepted by Phys. Rev. C