Inclusive open charm photoproduction in ultraperipheral collisions at the LHC with G${\hat{I}}^3$A-FONLL

Abstract

We compute the inclusive $D^0$ production cross section in ultraperipheral Pb-Pb collisions at the LHC as a function of the $D^0$ transverse momentum and rapidity. These calculations are carried out within the new G${\hat{I}}^3$A-FONLL (Generalized Photon-Nucleus FONLL) framework, which can predict photonuclear cross sections for charm and beauty hadrons in electron-proton, electron-nucleus, and ultraperipheral heavy-ion collisions. The framework relies on FONLL (Fixed-Order Next-to-Leading Logarithm) to model heavy-quark production in photonuclear collisions and employs a photon-flux reweighting procedure to describe the production cross sections in ultraperipheral heavy-ion collisions. The G${\hat{I}}^3$A calculations are first validated against the photoproduction cross sections of $D^{\ast }$ in electron-proton collisions at HERA. The predictions for the $D^0$ production cross section in ultraperipheral Pb-Pb collisions at the LHC are then presented and compared to the first experimental results obtained by CMS at $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}=5.36$ TeV. The predictions are benchmarked against different choices of nuclear parton distribution functions, fragmentation functions, and renormalization and factorization scales.

38 pages, 25 figures; minor corrections, version accepted to journal, updated references