Illuminating the impact-parameter dependence of UPC dijet photoproduction

2023/11/29 by K. Eskola, Eskola, Kari J., V. Guzey +7
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.2311.17611

openalex publication_date 2023/11/29 · openalex created_date 2023/12/01 · openalex updated_date 2026/07/28

Abstract

We present new NLO pQCD predictions for photoproduction of dijets in ultraperipheral PbPb collisions at 5.02 TeV with a realistic photon flux and up-to-date nuclear PDFs. Our calculation of the impact parameter dependence of the photon flux includes the effects of the nuclear form factor in the photon-emitting nucleus and the spatial dependence of nuclear PDFs of the target nucleus, which are estimated using the Wood-Saxon nuclear density profile. We show that a significant portion of the measured dijets at large z_γ originate from events with impact parameters of the order of a few nuclear radii, and that the cross section predictions therefore become sensitive to the modelling of the nuclear geometry and photon flux close to the source nucleus.

Related

• Collision geometry in UPC dijet production
• Dijet photoproduction and transverse-plane geometry in ultra-peripheral nucleus-nucleus collisions
• Spatial resolution of dijet photoproduction in near-encounter ultraperipheral nuclear collisions
• Inclusive and diffractive dijet photoproduction in ultraperipheral Pb-Pb collisions at the LHC
• Probing nuclear PDFs with dijets in ultra-peripheral Pb+Pb collisions