Momentum dependence of drag coefficients and heavy flavor suppression in quark gluon plasma

The momentum dependence of the drag coefficient of heavy quarks propagating through a quark gluon plasma (QGP) has been evaluated. The results have been used to estimate the nuclear suppression factor of charm and bottom quarks in a QGP. We observe that the momentum dependence of the transport coefficients plays crucial role in the suppression of the heavy quarks and, consequently, in discerning the properties of the QGP using heavy flavors as a probe. We show that the large suppression of the heavy quarks observed at the BNL Relativistic Heavy Ion Collider (RHIC) and at the CERN Large Hadron Collider (LHC) is predominantly due to the radiative losses. The suppression of D0 in Pb+Pb collisions at LHC energies--recently measured by the ALICE Collaboration--has also been studied.