Momentum transfer squared dependence of exclusive quarkonia photoproduction in ultraperipheral collisions

Summary, in English

We study fully differential quarkonia photoproduction observables in ultraperipheral collisions as functions of momentum transfer squared. We employ the dipole picture of the QCD part of the scattering with proton and nucleus targets, with the projectile being a quasireal photon flux emitted by an incoming hadron. We analyze such observables for ground J/ψ, (1S) and excited ψ′, (2S) states whose light-front wave functions are obtained in the framework of an interquark potential model incorporating the Melosh spin transformation. Two different low-x saturation models, one obtained by solving the Balitsky-Kovchegov equation with the collinearly improved kernel and the other with a Gaussian impact-parameter-dependent profile, are used to estimate the underlined theoretical uncertainties of our calculations. The results for the proton target and with charmonium in the final state are in agreement with the available HERA data, while in the case of the nucleus target we make predictions for γA and AA differential cross sections at different W and at s=5.02 TeV, respectively.