Langevin Dynamics of Heavy Quarks in a Soft-Hard Factorized Approach

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 2π TD_s(T_c) ≃ 6 . With the parameter-optimized model, we are able to describe simultaneously the prompt D^0 R_AA and v_2 data at p_T≤ 8 GeV in Pb–Pb collisions at √(s_NN)=2.76 and √(s_NN)=5.02 TeV. We also make predictions for non-prompt D^0 meson for future experimental tests down to the low momentum region.