https://doi.org/10.1140/epjc/s10052-008-0825-x
Regular Article - Theoretical Physics
Surface versus volume emissions in photon–hadron correlations
1
Institute of Particle Physics, Huazhong Normal University, Wuhan, 430079, China
2
Key Laboratory of Quark & Lepton Physics, Huzhong Normal University, Ministry of Education, Wuhan, 430079, China
3
Department of Physics, Shandong University, Jinan, 250100, China
4
Physics Department, Florida State University, Tallahassee, FL, 32306-4350, USA
5
Nuclear Science Division, Lawrence Berkeley Laboratory, Berkeley, CA, 94720, USA
* e-mail: zhanghz@iopp.ccnu.edu.cn
Received:
4
September
2008
Published online:
10
December
2008
High-p T photon–hadron correlations are studied within the next-to-leading order (NLO) perturbative QCD parton model with modified parton-jet fragmentation functions due to jet quenching in high-energy A+A collisions. In central A+A collisions, the away-side hadrons with large z T=p T h /p T γ are controlled mainly by the surface emission of the gamma-jet events, while a small z T region will be volume emission bias. In other words, gamma jets for a small-z T region probe the dense matter deeper than those gamma jets for a large-z T region, so the small-z T gamma jets are found to be slightly more sensitive to the properties of the dense matter than the large-z T gamma jets.
© Springer-Verlag , 2009
