Open charm photoproduction in UPCs at the LHC

Abstract

We present the calculation for  the open charm production in ultraperipheral collisions at the Large Hadron Collider. Predictions for $D^0$ photoproduction using the Generalized-Photon-Nucleus FONLL formalism are presented, extending previously developed framework for electron-proton and electron-nucleus collisions. The calculations are benchmarked against  the experimental data for $D^*$ production at HERA collider, with the  updated proton distribution function. We  present predictions for $D^0$ photoproduction in UPCs, including the photon flux from nucleus, and modifying it by the electromagnetic dissociation probability. The results in bins of transverse momentum and rapidity are compared to the  measurements from CMS experiment in UPC lead-lead collisions at $\sqrt{s_{NN}}=5.36$ TeV at the LHC. We quantify uncertainties due to the renormalization and factorization scale variation,  as well as the PDF and fragmentation function uncertainties.