  The drag force of charm quarks propagating through a thermalized system of
Quark Gluon Plasma (QGP) has been considered within the framework of both
conformal/non-conformal Anti de Sitter (AdS) correspondence. Newly derived
Einstein Fluctuation-Dissipation relation has been used to calculate the heavy
flavor diffusion coefficients. Using the drag and diffusion coefficients as
inputs Langevin equation has been solved to study the heavy flavor suppression
factor. It has been shown that within conformal AdS correspondence the D-meson
suppression at LHC energy can be reproduced where as the non-conformal AdS
correspondence fail to reproduce the experimental results. It suggests
collisional loss alone within non-conformal AdS correspondence can not
reproduce the experimental results and inclusion of radiative loss becomes
important.
