Langevin + Hydrodynamics Approach to Heavy Quark Propagation and Correlation in QGP

We develop a relativistic Langevin dynamics under the background of strongly interacting quark-gluon fluid described by the (3+1)-dimensional hydrodynamics. The drag force acting on charm and bottom quarks is parametrized according to the formula obtained from the anti-de-Sitter space/conformal field theory (AdS/CFT) correspondence. In this setup, we calculate the nuclear modification factor $R_{\rm{AA}}$ for the single-electrons from the charm and bottom quarks to extract the magnitude of the drag force from the PHENIX and STAR data. The $R_{\rm{AA}}$ for single-electrons with $p_{T}\geq 3$ GeV indicates that the drag force is close to the AdS/CFT prediction. Effects of the drag force on the elliptic flow of single-electrons are also discussed. Moreover, we predict the electron-muon correlation which is closely related to the heavy-quark pair correlation in hot matter.