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arXiv · 2102.04954

Radiative Decays of Charged Leptons in the Seesaw Effective Field Theory with One-loop Matching

Di Zhang·Shun Zhou
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Abstract

The canonical type-I seesaw model with three heavy Majorana neutrinos is one of the most natural extensions of the standard model (SM) to accommodate tiny Majorana masses of three ordinary neutrinos. At low-energy scales, Majorana neutrino masses and unitarity violation of lepton flavor mixing have been extensively discussed in the literature, which are respectively generated by the unique dimension-five Weinberg operator and one dimension-six operator in the seesaw effective field theory (SEFT) with the tree-level matching. In this work, we clarify that a self-consistent calculation of radiative decays of charged leptons $β^- \to α^- + γ$ requires the SEFT with one-loop matching, where new six-dimensional operators emerge and make important contributions. For the first time, the Wilson coefficients of all the relevant six-dimensional operators are computed by carrying out the one-loop matching between the effective theory and full seesaw model, and applied to calculate the total rates of radiative decays of charged leptons.

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Di Zhang, Shun Zhou. 2021-06-30. Radiative Decays of Charged Leptons in the Seesaw Effective Field Theory with One-loop Matching. https://doi.org/10.1016/j.physletb.2021.136463

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