English

One-Loop Integrals for Purely Virtual Particles

High Energy Physics - Phenomenology 2023-11-21 v2 High Energy Physics - Theory

Abstract

Quantum field theories with purely virtual particles, or fakeons, require suitable modifications in one-loop integrals. We provide the expressions for the modified scalar integrals in the case of the bubble, triangle and box diagrams. The new functions are defined by means of their difference with the `t Hooft-Veltman scalar integrals. The modifications do not affect the derivation of the Passarino-Veltman reduction and one-loop integrals with nontrivial numerators can be decomposed in the same fashion. Therefore, the new functions can be directly used to study the phenomenology of any models with standard particles and fakeons. We compare our results with standard amplitudes and show that the largest differences are often localized in relatively small energy ranges and are characterized by additional nonanalyticities. Finally, we give explicit examples in the context of a toy model, where cross sections and decay widths of standard particles are modified by the presence of fakeons.

Keywords

Cite

@article{arxiv.2209.05547,
  title  = {One-Loop Integrals for Purely Virtual Particles},
  author = {Aurora Melis and Marco Piva},
  journal= {arXiv preprint arXiv:2209.05547},
  year   = {2023}
}

Comments

34 pages, 9 figures. Sec. 2 rearranged, new example with plot in sec. 3, other minor corrections. Published version, prd

R2 v1 2026-06-28T01:09:45.720Z