JETP Letters: issues online

We calculate the medium modification factor I_pA for the photon-tagged jet fragmentation functions for scenario with the quark-gluon plasma formation in pA and pp collisions. We perform calculations of radiative and collisional parton energy loss in the quark-gluon plasma with running α_s which has a plateau around $Q\sim \kappa T$ with κ fitted to the LHC data on the heavy ion R_AA. We find that the theoretical predictions for I_pA in 5.02 TeV p + Pb collisions are within errors consistent with the data from ALICE [ALICE_IpA]. However, a definite conclusion about the presence or absence of jet quenching in pA collisions cannot be drawn due to large experimental errors of the ALICE data [ALICE_IpA]. Our calculations show that this requires a significantly more accurate measurement of I_pA.