Collision geometry in UPC dijet production

Authors

  • Petja Paakkinen University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland and Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland https://orcid.org/0000-0002-4811-0669
  • Kari J. Eskola University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland and Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland
  • Vadim Guzey University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland and Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland
  • lkka Helenius University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland and Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland
  • Hannu Paukkunen University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland and Helsinki Institute of Physics, P.O. Box 64, FI-00014 University of Helsinki, Finland

DOI:

https://doi.org/10.17161/qcs5kh43

Keywords:

inclusive photonuclear processes, jet photoproduction, perturbative QCD, impact-parameter dependence, neutron-class event dependence

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.

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Published

2025-03-11

Issue

UPC 2023: Proceedings of the International workshop on the physics of Ultra Peripheral Collisions

Section

Articles

License

Copyright (c) 2024 Petja Paakkinen, Kari J. Eskola, Vadim Guzey, lkka Helenius, Hannu Paukkunen

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.