Two-loop amplitudes for processes involving photons at Hadron Colliders

Abstract: Studies associated with processes with photons play an essential role at the Large Hadron Collider (LHC).
With their clean signal, they contributed significantly to the discovery of the Higgs particle.
In this thesis, we provide important building blocks for precision studies of processes including photons.
It is expected that in the decade to come, with the runs of the High Luminosity LHC, experimentalists will measure some of these processes at percent level precision.
Comparisons to the experiment will require that theoretical predictions include at least next-to-next-to-leading-order (NNLO) QCD and next-to-leading-order (NLO) electroweak corrections.
Some of the critical bottlenecks of NNLO calculations are double-virtual contributions, which require two-loop scattering amplitudes.
Obtaining those amplitudes can be challenging given the complex Feynman integrals that they include and the large intermediate expressions encountered when computing the coefficients of the integrals.
We present the computation of double-virtual corrections to two-photon and three-photon production at the LHC.
We obtained the needed multi-loop amplitudes using the numerical unitarity method to determine the master integral coefficients and employing functional reconstruction algorithms.
We achieved our result using Caravel, a numerical framework for the calculation of one- and two-loop helicity amplitudes, which we extended to include photons and the capability to operate in the physical region of phase space.
Our three-photon production amplitudes are the first publicly available expressions of any two-loop five-particle amplitude ready for phenomenological studies.
Our results have been used in a phenomenological calculation that has been compared with measurements by the ATLAS collaboration

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Sprache: Englisch
• Anmerkungen: Universität Freiburg, Dissertation, 2021

Klassifikation und Themen

• Schlagwort: Photons ; Hadron colliders

Beteiligte, Orts- und Zeitangaben

• Ereignis: Veröffentlichung
• (wo): Freiburg
• (wer): Universität
• (wann): 2022
• Urheber: Pascual, Evgenij
• Beteiligte Personen und Organisationen: Febres Cordero, Fernando ; Ita, Harald ; Febres Cordero, Fernando ; Dittmaier, Stefan ; Albert-Ludwigs-Universität Freiburg. Physikalisches Institut ; Albert-Ludwigs-Universität Freiburg. Abteilung für Reine Mathematik ; Albert-Ludwigs-Universität Freiburg. Fakultät für Mathematik und Physik

Weitere Informationen

• DOI: 10.6094/UNIFR/225647
• URN: urn:nbn:de:bsz:25-freidok-2256474
• Rechteinformation: Kein Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 25.03.2025, 13:51 MEZ