  We investigate long range rapidity correlations of pairs of prompt photon and
jet in the Color Glass Condensate (CGC) framework in proton-proton and
proton-nucleus collisions at RHIC and the LHC. We show that photon-jet
correlations exhibit long-range azimuthal collimation at near-side for low
transverse momenta of the produced photon and jet in high-multiplicity events.
These ridge-like features are strikingly similar to the observed ridge effect
for di-hadron correlations at RHIC and the LHC. We show that correlations in
the relative rapidity and the relative azimuthal angle between pairs of prompt
photon and jet strongly depend on the gluon saturation dynamics at small-x
kinematics and such measurements can help to understand the true origin of the
observed di-hadron ridge in p+A collisions, and address whether the ridge is a
universal phenomenon for all two particle correlations at high energy and high
multiplicity events. We also investigate if there is a ridge-like structure for
photon-hadron pair correlations at RHIC and the LHC. We found that the
hadronization of jet has non-trivial effects on the photon-jet correlations.
