The impact of jet quenching on $Z^0$-tagged jets in relativistic heavy-ion collisions at the Large Hadron Collider (LHC) is investigated. We employ Sharpa Monte Carlo program that combines next-to-leading order matrix elements with matched resummation of parton shower to compute the initial $Z^0$+jet production. The Linear Boltzmann Transport (LBT) model is then used to simulate the propagation, energy attenuation of and medium response induced by jet partons in the quark-gluon plasma. With both higher-order corrections and matched soft/collinear radiation as well as a sophisticated treatment of parton energy loss and medium response in LBT, our numerical calculations can provide the best description so far of all available observables of $Z^0$+jet simultaneously in both p+p and Pb+Pb collisions, in particular, the shift of the distribution in transverse momentum asymmetry $x_{ \rm jZ}=p_T^{ \rm jet}/p_T^Z$, the modification of azimuthal angle correlation in $\Delta\phi_{ \rm{ j}Z}=|\phi_{ \rm jet}-\phi_Z|$ and the overall suppression of average number of $Z^0$-tagged jets per boson $R_{ \rm jZ}$ at $\sqrt s =5.02$ TeV as measured by the CMS experiment. We also show that higher-order corrections to $Z^0$+jet production play an indispensable role in understanding $Z^0$+jet azimuthal angle correlation at small and intermediate $\Delta\phi_{ \rm jZ}$, and momentum imbalance at small $x_{ \rm jZ}$. Jet quenching of the sub-leading jets is shown to lead to suppression of $Z^0$+jet correlation at small azimuthal angle difference $\Delta\phi_{ \rm jZ}$ and at small $x_{ \rm jZ}$.
Categories: nucl-th hep-ph nucl-ex