Jet quenching and $\gamma$-jet correlation in high-energy heavy-ion collisions

Abstract

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 $\sqrt{s}=2.76$ 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 $z_\text{jet}=p_L/E_{\text{jet}}$ 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.