Ultraperipheral nuclear collisions as a source of heavy quarkonia

Heavy quarkonium production in ultraperipheral nuclear collisions (UPC) is described within the QCD dipole formalism. Realistic quarkonium wave functions in the Q Q over bar rest frame are calculated by solving the Schrodinger equation with a subsequent Lorentz boost to high energy. We rely on several realistic Q potentials, which allow us to describe well the quarkonium masses and decay widths, as well as data on diffractive electroproduction of quarkonia on protons. Nuclear effects are calculated with the phenom-enological dipole cross sections fitted to deep-inelastic scattering (DIS) data. The higher twist quark shadowing related to the lowest Q Q over bar Fock component of the photon, as well as the leading twist gluon shadowing, related to higher components containing gluons, are included. The results for coherent and incoherent photoproduction of charmonia and bottomonia in UPC of heavy nuclei are in good accord with available data from the LHC. They can also be verified in future experiments at electron-ion colliders.

Automated summary

In this study, heavy quarkonium production in ultraperipheral nuclear collisions (UPC) is described using the QCD dipole formalism. Realistic quarkonium wave functions were calculated by solving the Schrodinger equation and applying a Lorentz boost to high energy. Different Q potentials were used to accurately describe quarkonium masses, decay widths, and data on diffractive electroproduction. Nuclear effects were included using dipole cross sections fitted to deep-inelastic scattering (DIS) data. The results agree well with available data from the LHC and can be verified in future experiments at electron-ion colliders.