TMD parton shower effects in associated γ + jet production at the LHC

We investigate associated prompt photon and hadronic jet production at the LHC energies using the kT-factorization approach. Our consideration is based on the O(ααs2) off-shell gluon-gluon fusion subprocess g*g*→γqq¯ and several subleading quark-initiated contributions from O(ααs) and O(ααs2) subprocesses, taken into account in the conventional (collinear) QCD factorization. The transverse momentum–dependent (or unintegrated) gluon densities in a proton are derived from Catani-Ciafaloni-Fiorani-Marchesini evolution equation. We achieve reasonably good agreement with the experimental data taken by CMS and ATLAS Collaborations and demonstrate the importance of initial-state parton showers for jet determination in the kT-factorization approach.