Work

Collision geometry in UPC dijet production

Year: 2025

Type: conference-paper

Abstract: We present a comprehensive NLO pQCD study on inclusive dijet photoproduction in ultraperipheral nucleus-nucleus collisions (UPCs). Our analysis takes into account the finite size of both the photon-emitting and the target nucleus, estimated using the Wood-Saxon nuclear density profile. We show that a significant part of the measured dijets at large z_\gamma in UPC Pb+Pb collisions at 5.02 TeV come from events with relatively small impact parameters of the order of a few nuclear radii, and the cross section predictions thus become sensitive to the modelling of the collision geometry and photon flux near the source nucleus. In addition, we include the modelling of electromagnetic breakup survival factor needed for a direct comparison with the experimental data and study the resolution power of this process in terms of the impact-parameter dependent nuclear parton distribution functions.

Source: Proceedings of the International Workshop on the Physics of Ultra Peripheral Collisions

DOI: 10.17161/qcs5kh43

Authors: Petja Paakkinen, Kari J. Eskola, Vadim Guzey, Lkka Helenius, Hannu Paukkunen

Institutions: University of Helsinki, Helsinki Institute of Physics, University of Jyväskylä

Language: English

Topic: High-Energy Particle Collisions Research

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: China Scholarship Council, H2020 European Research Council

Award: Yoctosecond imaging of QCD collectivity using jet observables