Exclusive and dissociative J/ψ photoproduction, and exclusive dimuon production, in p-Pb collisions at sNN =8.16 TeV

Abstract

The ALICE Collaboration reports three measurements in ultraperipheral proton-lead collisions at forward rapidity. The exclusive two-photon process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and the exclusive photoproduction of $J/\ensuremath{\psi}$ are studied. $J/\ensuremath{\psi}$ photoproduction with proton dissociation is measured for the first time at a hadron collider. The cross section for the two-photon process of dimuons in the invariant mass range from 1 to $2.5\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ agrees with leading-order quantum electrodynamics calculations. The exclusive and dissociative cross sections for $J/\ensuremath{\psi}$ photoproductions are measured for photon-proton center-of-mass energies from 27 to 57 GeV. They are in good agreement with HERA results.