  The space-time propagation of heavy quarks in ultra-relativistic heavy ion
collisions is studied within the partonic transport model Boltzmann Approach of
MultiParton Scatterings (BAMPS). In this model heavy quarks interact with the
partonic medium via binary scatterings. The cross sections for these
interactions are calculated with leading order perturbative QCD, but feature a
more precise Debye screening derived within the hard thermal loop approximation
and obey the running of the coupling. Within this framework the elliptic flow
and the nuclear modification factor of heavy quarks are computed for RHIC and
LHC energies and compared to available experimental data. It is found that
binary scatterings alone cannot reproduce the data and, therefore, radiative
corrections have to be taken into account.
