Quarkonium plus prompt-photon associated hadroproduction and nuclear shadowing

Abstract

The quarkonium hadroproduction in association with a photon at high energies provides a probe of the dynamics of the strong interactions as it is dependent on the nuclear gluon distribution. Therefore, it could be used to constrain the behavior of the nuclear gluon distribution in protonnucleus and nucleus-nucleus collisions. Such processes are useful to single out the magnitude of the shadowing/antishadowing effects in the nuclear parton densities. In this work we investigate the influence of nuclear effects in the production of J/ψ + γ and Υ + γ and estimate the transverse momentum dependence of the nuclear modification factors. The theoretical framework considered in the J/ψ (Υ) production associated with a direct photon at the hadron collider is the non-relativistic QCD (NRQCD) factorization formalism.

Diffractive quarkonium production in association with a photon at the LHC

“…As we will verify, the ratio of single diffractive production cross section to the inclusive production cross section is not strongly sensitive to the heavy quarkonium production mechanism. This channel has been recently investigated in the context of heavy ion collisions [6] and it can also to be compared to the previous calculations on diffractive quarkonium production [7].…”