English

One-loop contributions to decays $e_b\to e_a \gamma$ and $(g-2)_{e_a}$ anomalies, and Ward identity

High Energy Physics - Phenomenology 2023-06-02 v2

Abstract

In this paper, we will present analytic formulas to express one-loop contributions to lepton flavor violating decays ebeaγe_b\to e_a \gamma, which are also relevant to the anomalous dipole magnetic moments of charged leptons eae_a. These formulas were computed in the unitary gauge, using the well-known Passarino-Veltman notations. We also show that our results are consistent with those calculated previously in the 't Hooft-Veltman gauge, or in the limit of zero lepton masses. At the one-loop level, we show that the appearance of fermion-scalar-vector type diagrams in the unitary gauge will violate the Ward Identity relating to an external photon. As a result, the validation of the Ward Identity guarantees that the photon always couples with two identical particles in an arbitrary triple coupling vertex containing a photon.

Keywords

Cite

@article{arxiv.2301.05407,
  title  = {One-loop contributions to decays $e_b\to e_a \gamma$ and $(g-2)_{e_a}$ anomalies, and Ward identity},
  author = {L. T. Hue and H. N. Long and V. H. Binh and H. L. T. Mai and T. Phong Nguyen},
  journal= {arXiv preprint arXiv:2301.05407},
  year   = {2023}
}

Comments

The version accepted to Nuclear Physics B