# Nucleon dissociation and incoherent $J/\psi$ photoproduction on nuclei in ion ultraperipheral collisions at the CERN Large Hadron Collider

Guzey, V. (Department of Physics, University of Jyväskylä, P.O. Box 35, 40014 University of Jyväskylä, Finland) (Helsinki Institute of Physics, P.O. Box 64, 00014 University of Helsinki, Finland) (National Research Center “Kurchatov Institute,” Petersburg Nuclear Physics Institute (PNPI), Gatchina 188300, Russia) ; Strikman, M. (Department of Physics, The Pennsylvania State University, State College, Pennsylvania 16802, USA) ; Zhalov, M. (National Research Center “Kurchatov Institute,” Petersburg Nuclear Physics Institute (PNPI), Gatchina 188300, Russia)

11 January 2019

Abstract: Using the general notion of cross section fluctuations in hadron-nucleus scattering at high energies, we derive an expression for the cross section of incoherent $J/\psi$ photoproduction on heavy nuclei $d{\sigma }_{\gamma A\to J/\psi Y}/dt$, which includes both elastic $d{\sigma }_{\gamma p\to J/\psi p}/dt$ and proton-dissociation $d{\sigma }_{\gamma p\to J/\psi Y}/dt$ photoproduction on target nucleons. We find that, with good accuracy, $d{\sigma }_{\gamma A\to J/\psi Y}/dt$ can be expressed as a product of the sum of the $d{\sigma }_{\gamma p\to J/\psi p}/dt$ and $d{\sigma }_{\gamma p\to J/\psi Y}/dt$ cross sections, which have been measured at HERA, and the common nuclear shadowing factor, which is calculated using the leading twist nuclear shadowing model. Our prediction for the cross section of incoherent $J/\psi$ photoproduction in Pb-Pb ultraperipheral collisions at $\sqrt{{s}_{NN}}=2.76\phantom{\rule{0.28em}{0ex}}\mathrm{TeV}$ and $y=0,\phantom{\rule{0.28em}{0ex}}d{\sigma }_{AA\to J/\psi AY}\left(y=0\right)/dy=0.59-1.24\phantom{\rule{0.28em}{0ex}}\mathrm{mb}$ agrees within significant theoretical uncertainties with the data of the ALICE Collaboration.

Published in: Physical Review C 99 (2019)