Saved in:
Bibliographic Details
Main Authors: Butterworth, J. M., Helenius, I. M., Castella, J. J. Juan, Pattengale, B., Sanjrani, S., Wing, M.
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2408.15842
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929631882379264
author Butterworth, J. M.
Helenius, I. M.
Castella, J. J. Juan
Pattengale, B.
Sanjrani, S.
Wing, M.
author_facet Butterworth, J. M.
Helenius, I. M.
Castella, J. J. Juan
Pattengale, B.
Sanjrani, S.
Wing, M.
contents Modelling the underlying event in high-energy hadronic collisions is important for physics at colliders. This includes lepton colliders, where low-virtuality photons accompanying the lepton beam(s) may develop hadronic structure. Similarly, photon-induced collisions also occur in proton or heavy-ion beam experiments. While the underlying event in proton-proton collisions has been the subject of much study at the LHC, studies of hadronic-photon-induced underlying event are now of increasing interest in light of planned future lepton and lepton-hadron colliders, as well as the photon-induced processes in ultra-peripheral collisions at the LHC. Here we present an investigation of the underlying event in photon-initiated processes, starting from the PYTHIA models used to describe LHC and Tevatron data, and revisiting HERA and LEP2 data. While no single tune describes all the data with different beam configurations, we find that a good agreement can still be found within the same model by adjusting the relevant parameters separately for $γγ$, $γp$ and $pp$. This suggests that the basic model of multiparton interaction implemented in PYTHIA can be applied for different beam configurations. Furthermore, we find that a reasonable agreement for $γγ$ and $γp$ data, and for $pp$ data at an LHC reference energy, can be found within a single parametrization, but $pp$ collisions would prefer a stronger energy dependence, leading to too many multiparton interactions in lower energy photon-induced collisions. On this basis, we make some recommendations for simulations of photon-induced processes, such as $γγ$ events at the LHC or FCC and $ep$ or $eA$ collisions at the EIC, and suggest possibilities for improvements in the modelling.
format Preprint
id arxiv_https___arxiv_org_abs_2408_15842
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Modelling the underlying event in photon-initiated processes
Butterworth, J. M.
Helenius, I. M.
Castella, J. J. Juan
Pattengale, B.
Sanjrani, S.
Wing, M.
High Energy Physics - Phenomenology
High Energy Physics - Experiment
Modelling the underlying event in high-energy hadronic collisions is important for physics at colliders. This includes lepton colliders, where low-virtuality photons accompanying the lepton beam(s) may develop hadronic structure. Similarly, photon-induced collisions also occur in proton or heavy-ion beam experiments. While the underlying event in proton-proton collisions has been the subject of much study at the LHC, studies of hadronic-photon-induced underlying event are now of increasing interest in light of planned future lepton and lepton-hadron colliders, as well as the photon-induced processes in ultra-peripheral collisions at the LHC. Here we present an investigation of the underlying event in photon-initiated processes, starting from the PYTHIA models used to describe LHC and Tevatron data, and revisiting HERA and LEP2 data. While no single tune describes all the data with different beam configurations, we find that a good agreement can still be found within the same model by adjusting the relevant parameters separately for $γγ$, $γp$ and $pp$. This suggests that the basic model of multiparton interaction implemented in PYTHIA can be applied for different beam configurations. Furthermore, we find that a reasonable agreement for $γγ$ and $γp$ data, and for $pp$ data at an LHC reference energy, can be found within a single parametrization, but $pp$ collisions would prefer a stronger energy dependence, leading to too many multiparton interactions in lower energy photon-induced collisions. On this basis, we make some recommendations for simulations of photon-induced processes, such as $γγ$ events at the LHC or FCC and $ep$ or $eA$ collisions at the EIC, and suggest possibilities for improvements in the modelling.
title Modelling the underlying event in photon-initiated processes
topic High Energy Physics - Phenomenology
High Energy Physics - Experiment
url https://arxiv.org/abs/2408.15842