Photons in the proton: implications for the LHC

Jan 16, 2024
32 pages
Published in:
  • Eur.Phys.J.C 84 (2024) 5, 540
  • Published: May 28, 2024
e-Print:
Report number:
  • TIF-UNIMI-2023-17,
  • Edinburgh 2023/19,
  • CERN-TH-2023-159
Experiments:

Citations per year

202320242025118
Abstract: (Springer)
We construct a set of parton distribution functions (PDFs), based on the recent NNPDF4.0 PDF set, that also include a photon PDF. The photon PDF is constructed using the LuxQED formalism, while QED evolution accounting for O(α){\mathcal {O}}\left( \alpha \right) , O(ααs){\mathcal {O}}\left( \alpha \alpha _s\right) , and O(α2){\mathcal {O}}\left( \alpha ^2\right) corrections is implemented and benchmarked by means of the EKO code. We investigate the impact of QED effects on NNPDF4.0, and compare our results both to our previous NNPDF3.1QED PDF set and to other recent PDF sets that include the photon. We assess the impact of photon-initiated processes and electroweak corrections on a variety of representative LHC processes, and find that they can reach the 5% level in vector boson pair production at large invariant mass.
Note:
  • 32 pages, 19 figures. Final; version, as published on EPJC. Pheno discussion in Sect 4.2 improved, a few typos corrected
  • parton: distribution function
  • quantum electrodynamics: effect
  • electroweak interaction: correction
  • vector boson: pair production
  • photon
  • CERN LHC Coll
  • neural network