Semi-inclusive photon-hadron production in pp and pA collisions at RHIC and LHC

Understand

We investigate semi-inclusive photon-hadron production in the color glass condensate (CGC) framework at RHIC and the LHC energies in proton-proton (pp) and proton-nucleus (pA) collisions.

• We calculate the coincidence probability for azimuthal correlation of pairs of photon-hadron and show that the away-side correlations have a double-peak or a single-peak structure depending on trigger particle selection and kinematics.
• This novel feature is unique for semi-inclusive photon-hadron production compared to a similar measurement for double inclusive dihadron production in pA collisions.
• We obtain necessary conditions between kinematics variables for the appearance of a double-peak or a single peak structure for the away-side photon-hadron correlations in pp and pA collisions at forward rapidities and show that this feature is mainly controlled by the ratio p_T^hadron/p_T^photon.