System-size dependence of <i>γ</i>-jet modifications in heavy-ion collisions*

Abstract Medium modifications of γ -triggered jets are investigated with the linear Boltzmann transport model in heavy-ion collisions with varying system sizes, focusing on centrality dependence in Pb+Pb and Xe+Xe collisions at the LHC. Our numerical results reveal that jets produced in central collisions exhibit a wider transverse asymmetry ( ) distribution, broader jet shape, and more pronounced γ -jet transverse momentum imbalance ( ) compared with peripheral collisions. These effects arise from the longer path length and stronger jet-medium interactions in central collisions, leading to enhanced jet quenching and medium response. Our findings demonstrate that the magnitude of γ -jet modifications is sensitive to the size and centrality of the collision system, with larger systems inducing more significant alterations owing to increased energy loss and medium feedback.