Exploration of jet energy loss via direct $\gamma$-charged particle azimuthal correlation measurements

Abstract

The multiplicities of charged particles azimuthally associated with direct photons and ${\pi }^0$ have been measured for Au+Au, p+p, and d+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV in the STAR experiment. Charged particles with transverse momentum 0.5 $<$ $p_T^{h^{\pm }}$ $<$ 16 GeV/c for p+p and d+Au, and 3 $<$ $p_T^{h^{\pm }}$ $<$ 16 GeV/c for Au+Au and pseudorapidity $\mid \eta \mid$ $\le$ 1.5 in coincidence with direct photons and ${\pi }^0$ of high transverse momentum 8 $<$ $p_T^{\gamma ,{\pi }^0}$ $<$ 16 GeV/c at $\mid \eta \mid$ $\le$ 0.9 have been used for this analysis. Within the considered range of kinematics, the observed suppressions of the associated yields per direct $\gamma$ in central Au+Au relative to p+p and d+Au are similar and constant with direct photon fractional energy $z_T$ ($z_T=p_T^{h^{\pm }}/p_T^{\gamma }$). The measured suppressions of the associated yields with direct $\gamma$ are comparable to those with ${\pi }^0$. The data are compared to theoretical predictions.

4 pages, 5 figures, Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee

References in corpus (1)

• Direct observation of dijets in central Au+Au collisions at sqrt(s_NN) = 200 GeV

Cited by in corpus (3)

• Dependence of direct detection signals on the WIMP velocity distribution
• Jet-Medium Interactions with Identified Particles
• Jet Medium interactions at Quark Matter 09