Kinematics of Heavy Quark Radiative Energy Loss in Viscous QCD Plasma

We present effects of longitudinal expansion of QCD medium on radiative energy loss suffered by heavy quark in a dynamically screened medium. The energy loss expression to the first order in opacity is obtained by incorporating viscous corrections to the equilibrium phase-space distribution function as well as expansion of the medium. Theoretical formalism accounts for medium modified polarization tensor and time dependent cooling because of rapid longitudinal expansion of the QCD medium in relativistic heavy ion collision experiments along with modified phase space. For manifestation we have used distribution function obtained from Grad's 14-moment expansion in relativistic viscous hydrodynamic evolution. Viscous correction is shown to enhance the radiative energy loss and the result is time dependent. We have also shown eta/s dependence of radiative energy loss for the Grad's 14-moment distribution function. Our results for energy loss lie within the static plasma results and results obtained considering only ideal Bjorken expansion.