In collisions of ultrarelativistic nuclei, photon-tagged jets provide a unique opportunity to compare jet production and modification due to parton shower formation and propagation in strongly interacting matter at vastly different center-of-mass energies. We present first results for the cross sections of jets tagged by an isolated photon to $O({\alpha }_{\mathrm{em}}{\alpha }_s^2)$ in central $\mathrm{Au}+\mathrm{Au}$ reactions with $\sqrt{s_{NN}}=200\mathrm{GeV}$ at RHIC and central $\mathrm{Pb}+\mathrm{Pb}$ reactions with $\sqrt{s_{NN}}=2.76\mathrm{TeV}$ at LHC. We evaluate the increase in the transverse momentum imbalance of the observed $\gamma +\mathrm{\text{jet}}$ state, induced by the dissipation of the parton shower energy due to strong final-state interactions. Theoretical predictions to help interpret recent and upcoming experimental data are presented.

• Received 7 August 2012

DOI:https://doi.org/10.1103/PhysRevLett.110.142001