Nuclear Effects in Prompt Photon Production at the Large Hadron Collider

Abstract

We present a detailed study of prompt photon production cross section in heavy-ion collisions in the central rapidity region at energy of $\sqrt{s}=5.5$ TeV, appropriate to LHC experiment. We include the next-to-leading order radiative corrections, $O({\alpha }_{em}{\alpha }_s^2)$, nuclear shadowing and the parton energy loss effects. We find that the nuclear effects can reduce the invariant cross section for prompt photon production by an order of magnitude at $p_t=3$ GeV. We discuss theoretical uncertainties due to parton energy loss and nuclear shadowing parameters. We show that the K-factor, which signifies the importance of next-to-leading order corrections, is large and has a strong $p_t$ dependence.

Comments: version accepted for publication in Nucl. Phys. A