Azimuthal correlations between charged hadrons and direct photons at high-p${}_t$ in $p+p$ and $Au+Au$ collisions at $\sqrt{s_{NN}}$ = 200 GeV

Abstract

Recent results at STAR for direct $\gamma$-charged hadron azimuthal correlations in heavy-ion collisions are presented. These correlations are used to study the color charge density of the medium through the medium-induced modification of high-p${}_T$ parton fragmentation. Azimuthal correlations of direct photons at high transverse energy 8 $<$ E${}_T$ $<$ 16 GeV with away-side charged hadrons of transverse momentum 3 $<$ p${}_T$ $<$ 6 GeV/c have been measured over a broad range of centrality for $Au+Au$ collisions and $p+p$ collisions at $\sqrt{s_{NN}}$ = 200 GeV in the STAR experiment. The per-trigger away-side yield of direct $\gamma$ is smaller than from ${\pi }^0$ triggers in the same centrality class.

4 pages, 5 figures, 34${}^{\mathrm{th}}$ International Conference on High Energy Physics, Philadelphia, 2008

References in corpus (1)

• Modified Fragmentation Function in Heavy Ion Collisions at RHIC via Direct photon-Jet Measurements