A Linear Boltzmann Transport model within perturbative QCD is developed for the study of parton propagation inside the quark-gluon plasma. Both leading partons and thermal recoil partons are tracked so that one can also study jet-induced medium excitations. In this study, we implement the complete set of elastic parton scattering processes and investigate elastic parton energy loss, transverse momentum broadening and their nontrivial energy and length dependence. We further investigate medium modifications of the jet shape and fragmentation functions of reconstructed jets. Contributions from thermal recoil partons are found to have significant influences on jet shape, fragmentation functions and angular distribution of reconstructed jets.

γ-jet production is considered one of the best probes of the hot quark-gluon plasma in high-energy heavy-ion collisions since the direct γ can be used to gauge the initial energy and momentum of the associated jet. This is investigated within the Linear Boltzmann Transport (LBT) model for jet propagation and jet-induced medium excitation. With both parton energy loss and medium response from jet-medium interaction included, LBT can describe experimental data well on γ-jet correlation in Pb+Pb collisions at the Large Hadron Collider. Multiple jets associated with direct γ production are found to contribute significantly to γ-jet correlation at small p jet T < p γ T and large azimuthal angle relative to the opposite direction of γ. Jet medium interaction not only suppresses the leading jet at large p jet T but also sub-leading jets at large azimuthal angle. This effectively leads to the narrowing of γ-jet correlation in azimuthal angle instead of broadening due to jet-medium interaction. The γ-jet profile on the other hand will be broadened due to jet-medium interaction and jet-induced medium response. Energy flow measurements relative to the direct photon is illustrated to reflect well the broadening and jet-induced medium response.

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The suppression factor for single inclusive jets in Pb+Pb collisions at the Large Hadron Collider (LHC) has a weak dependence on the transverse momentum pT and remains almost the same at two colliding energies, √ s = 2.76 and 5.02 TeV, though the central rapidity density of bulk hadrons increases by about 20%. This phenomenon is investigated within the Linear Boltzmann Transport (LBT) model, which includes elastic and inelastic processes based on perturbative QCD for both jet shower and recoil medium partons as they propagate through a quark-gluon plasma (QGP). With the dynamic evolution of the QGP given by the 3+1D CLVisc hydrodynamic model with event-byevent fully fluctuating initial conditions, single inclusive jet suppression in Pb+Pb collisions from LBT agrees well with experimental data. The weak √ s and pT -dependence of the jet suppression factor at LHC are found to result directly from the √ s-dependence of the initial jet pT spectra and slow pT -dependence of the jet energy loss. Contributions from jet-induced medium response, influence of radial expansion, both of which depend on jet-cone size, and jet flavor composition all conjoin to give a slow pT -dependence of jet energy loss and the single jet suppression factor RAA, their dependence on √ s and jet-cone size. Single inclusive jet suppression at √ s = 200 GeV is also predicted that actually decreases slightly with pT in the pT < 50 GeV/c range because of the steeper initial jet spectra though the pT -dependence of the jet energy loss is weaker than that at LHC.