Langevin dynamics of heavy quarks in a soft-hard factorized approach

Abstract

By utilizing a soft-hard factorized model, which combines a thermal perturbative description of soft scatterings and a perturbative QCD-based calculation for hard collisions, we study the energy and temperature dependence of the heavy quark diffusion coefficients in Langevin dynamics. The adjustable parameters are fixed from the comprehensive model-data comparison. We find that a small value of the spatial diffusion coefficient at transition temperature is preferred by data $2\pi T{D}_s(T_c)\simeq 6$. With the parameter-optimized model, we are able to describe simultaneously the prompt $D^0$ $R_{\mathrm{AA}}$ and $v_2$ data at $p_{\mathrm{T}}\le 8$ GeV in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ and $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. We also make predictions for non-prompt $D^0$ meson for future experimental tests down to the low momentum region.

Comments: 13 pages, 10 figures