SciPost logo

SciPost Submission Page

Flavor violating $\ell_i$ decay into $\ell_j$ and a light gauge boson

by Alejandro Ibarra, Marcela Mar\'in and Pablo Roig

This Submission thread is now published as

Submission summary

Authors (as registered SciPost users): Marcela Marín · Pablo Roig
Submission information
Preprint Link: scipost_202112_00005v1  (pdf)
Date accepted: Jan. 14, 2025
Date submitted: Dec. 3, 2021, 9:32 p.m.
Submitted by: Marcela Marín
Submitted to: SciPost Physics Proceedings
Proceedings issue: 16th International Workshop on Tau Lepton Physics (TAU2021)
Ontological classification
Academic field: Physics
Specialties:
  • High-Energy Physics - Phenomenology
Approach: Phenomenological

Abstract

The $\ell_i\to\ell_j\chi$ decays, with $\chi$ a boson associated to the $U(1)_\chi$ symmetry, have not been described satisfactorily so far for light spin-one $\chi$. In particular, observables exhibited an unphysical divergence in the limit of massless $\chi$, associated to its longitudinal polarizations. Based on gauge symmetry, we show how to correct this issue. To this end, we consider two general models realizing the effective field theory description. Being the LFV generated either at tree level or at one loop, these processes are well behaved for light $m_\chi$. We discuss the most salient phenomenological consequences and its relevance in the searches for this kind of decays.

Published as SciPost Phys. Proc. 16, 011 (2025)

Reports on this Submission

Report #1 by Swagato Banerjee (Referee 1) on 2024-11-28 (Invited Report)

  • Cite as: Swagato Banerjee, Report on arXiv:scipost_202112_00005v1, delivered 2024-11-28, doi: 10.21468/SciPost.Report.10218

Report

Neutrinoless lepton-flavor-violating decays of a heavy lepton to a light lepton and a light gauge boson associated with a U(1) symmetry are studied. Lepton flavor violation are realized either at tree level or at the one loop level with two general models realizing the effective field theory description. The most general effective parametrization of the interaction between two charged leptons and a massive gauge boson, yields the decay rate in terms of the corresponding form factors. For these two models, the ratio of rates of a heavy lepton decaying to a light lepton and a gauge boson to the rates of a heavy lepton decaying to three light leptons is in the order of a factor between one and twenty in the range of masses considered. Taking into account that the limits of the latter decays are much more stringent than those on the former, it is evident that the upper limits on a heavy lepton decaying to a light lepton and a gauge boson need to improve by five to six orders of magnitude to potentially observe a signal.

Recommendation

Publish (surpasses expectations and criteria for this Journal; among top 10%)

  • validity: -
  • significance: -
  • originality: -
  • clarity: -
  • formatting: -
  • grammar: -

Login to report or comment