Single Electron Transverse Momentum and Azimuthal Anisotropy Distributions: Charm Hadron Production at RHIC

Abstract

Quantum Chromodynamics (QCD) is a basic gauge field theory to describe strong interactions. Lattice QCD calculations predict a phase transition from hadronic matter to a deconfined, locally thermalized Quark-Gluon Plasma (QGP) state at high temperature and small baryon density. Plenty of exciting results from RHIC experiments in the first three years have demonstrated that a hot dense matter with strong collective motion which cannot be described with hadronic degrees of freedom was created at RHIC. Charm quarks are believed to be mostly created from initial gluon fusion in heavy ion collisions. Since they are massive, charm hadrons are proposed to be ideal probes to study the early stage dynamics in heavy ion collisions. We provide here an indirect measurement of charm semi-leptonic decay. Single electron transverse momentum ($p_T$) distributions from 200 GeV \dAu, \pp collisions and 62.4 GeV \AuAu collisions, and single electron azimuthal anisotropy ($v_2$) from 62.4 GeV \AuAu collisions are presented. (Abridged)