Nuclear modification of electron spectra and implications for heavy quark energy loss in Au+Au collisions at √s_NN=200 GeV

Abstract

The PHENIX experiment has measured midrapidity (|η|<0.35) transverse momentum spectra (0.4<p_T<5.0 GeV/c) of electrons as a function of centrality in Au+Au collisions at √s_NN=200 GeV. Contributions from photon conversions and from light hadron decays, mainly Dalitz decays of π⁰ and η mesons, were removed. The resulting nonphotonic electron spectra are primarily due to the semileptonic decays of hadrons carrying heavy quarks. Nuclear modification factors were determined by comparison to nonphotonic electrons in p+p collisions. A significant suppression of electrons at high p_T is observed in central Au+Au collisions, indicating substantial energy loss of heavy quarks.