Open heavy flavor and J/psi at RHIC and LHC

The suppression and collective flow of open and hidden heavy flavor in ultra-relativistic heavy ion collisions is studied with the partonic transport model Boltzmann Approach to MultiParton Scatterings (BAMPS). Charm and bottom quarks interact with the rest of the medium via elastic scatterings with an improved Debye screening and a running coupling. Heavy flavor electron data from RHIC can only be described if the cross section is multiplied with K=3.5 to mimic the contribution from radiative processes. With the same value for K we compare to elliptic flow data of D mesons at the LHC and find a good agreement. However, the nuclear modification factor of D mesons, non-prompt J/psi, muons, and electrons at the LHC is underestimated in our calculations. In addition, we present first BAMPS results on the suppression and elliptic flow of J/psi mesons, which are treated in the same framework.Comment: 4 pages, 3 figures, minor text modifications in version 2, Proceedings for Hard Probes 2012, Cagliari, Ital

Production, elliptic flow and energy loss of heavy quarks in the quark-gluon plasma

Production, elliptic flow and the nuclear modification factor of charm and bottom quarks are studied in central and non-central heavy-ion collisions at RHIC and LHC using the partonic transport model Boltzmann Approach of MultiParton Scatterings (BAMPS). Employing an initial heavy quark yield obtained with PYTHIA the full space-time evolution of charm and bottom quarks in the quark-gluon plasma (QGP) is carried out with BAMPS, taking also secondary production in the QGP into account. Only elastic collisions of heavy quarks with particles from the medium cannot describe the experimentally observed elliptic flow and nuclear modification factor. However, using an improved Debye screening and the running coupling yields a result which is much closer to data.Comment: 4 pages, 1 figure, to appear in the conference proceedings of Hot Quarks 2010, few minor modifications in 2nd versio

Open heavy flavor in Pb+Pb collisions at sqrt(s)=2.76 TeV within a transport model

The space-time evolution of open heavy flavor is studied in Pb+Pb collisions at sqrt(s)=2.76 TeV using the partonic transport model Boltzmann Approach to MultiParton Scatterings (BAMPS). An updated version of BAMPS is presented which allows interactions among all partons: gluons, light quarks, and heavy quarks. Heavy quarks, in particular, interact with the rest of the medium via binary scatterings with a running coupling and a Debye screening which is matched by comparing to hard thermal loop calculations. The lack of radiative processes in the heavy flavor sector is accounted for by scaling the binary cross section with a phenomenological factor K=3.5, which describes well the elliptic flow v_2 and nuclear modification factor R_AA at RHIC. Within this framework we calculate in a comprehensive study the v_2 and R_AA of all interesting open heavy flavor particles at the LHC: electrons, muons, D mesons, and non-prompt J/psi from B mesons. We compare to experimental data, where it is already available, or make predictions. To do this accurately next-to-leading order initial heavy quark distributions are employed which agree well with proton-proton data of heavy flavor at sqrt(s)=7 TeV.Comment: 7 pages, 10 figures, muon calculations updated, references added, published versio