Speaker
Description
We explore the possibility to use Ultra-Peripheral proton-lead Collisions (UPC) at the LHC to study inclusive vector-quarkonium photoproduction. Due to the extremely large energies of the colliding hadrons circulating in the LHC, the range of accessible photon-nucleon centre-of-mass energies largely exceeds what has been and will be studied at lepton-hadron colliders, HERA and the EIC.
We perform an extrapolation from HERA data to predict the yields of photoproduced $J/\psi$ and $\Upsilon$ mesons in proton-lead UPC and for $J/\psi$ mesons we estimate the transverse-momentum reach at the four LHC experiments. We demonstrate that inclusive photoproduction can be isolated from background processes by imposing constraints on the hadronic activity in the lead-going direction at either mid, forward, or far-forward rapidities depending, on the capability of the used detector. We find that a measurement of the cross sections is possible at ALICE, ATLAS, CMS, and LHCb. In addition, we propose and assess the Jacquet-Blondel method to reconstruct the photon-nucleon centre-of-mass energy and elasticity of the reaction, useful to separate out the resolved-photon contribution.