Jet quenching and γ-jet correlation in high-energy heavy-ion collisions

Medium modification of gamma-tagged jets in high-energy heavy-ion collisions is investigated within a linearized Boltzmann transport model which includes both elastic parton scattering and induced gluon emission. In Pb + Pb collisions at root s = 2.76 TeV, a gamma-tagged jet is seen to lose 15% of its energy at 0-10% central collisions. Simulations also point to a sizable azimuthal angle broadening of gamma-tagged jets at the tail of a distribution which should be measurable when experimental errors are significantly reduced. An enhancement at large z(jet) = p(L)/E-jet in jet fragmentation function at the Large Hadron Collider (LHC) can be attributed to the dominance of leading particles in the reconstructed jet. A gamma-tagged jet fragmentation function is shown to be more sensitive to jet quenching, therefore a better probe of the jet transport parameter. (c) 2014 Elsevier B.V. All rights reserved.