Recent PHENIX measurements on open heavy flavor electrons and hadrons correlations

Abstract

Perturbative QCD predicts that heavy quarks should lose significantly less energy traversing a dense, colored medium than light quarks. However, PHENIX measurements of heavy flavor decay electrons in Au+Au collisions indicate suppression nearly at the level of the π 0. Furthermore, a large azimuthal asymmetry of heavy flavor electrons is observed. A key experimental technique to investigate the mechanism of this unexpected energy loss is study of azimuthal correlations between heavy flavor decay electrons and charged hadrons. We measure such correlations in p + p collisions to provide a reference in the absence of medium. Any changes in Au + Au collisions then provide information on the energy flow from the traversing heavy quarks to the medium. Comparison to light hadron correlations highlight differences in the mechanism of heavy and light quark energy loss in the medium. We observe the away side jet shape and associated particle yields to be modified in Au + Au collisions.