Exact one-loop results for $$l_i \rightarrow l_j\gamma $$ li→ljγ in 3-3-1 models

Abstract We investigate the decays $$l_i\rightarrow l_j \gamma $$ li→ljγ , with $$l_i=e,\mu ,\tau $$ li=e,μ,τ in a general class of 3-3-1 models with heavy exotic leptons with arbitrary electric charges. We present full and exact analytical results keeping external lepton masses. As a by product, we...

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Bibliographic Details
Main Authors: L. T. Hue, L. D. Ninh, T. T. Thuc, N. T. T. Dat
Format: Article
Language:English
Published: SpringerOpen 2018-02-01
Series:European Physical Journal C: Particles and Fields
Online Access:http://link.springer.com/article/10.1140/epjc/s10052-018-5589-3
Description
Summary:Abstract We investigate the decays $$l_i\rightarrow l_j \gamma $$ li→ljγ , with $$l_i=e,\mu ,\tau $$ li=e,μ,τ in a general class of 3-3-1 models with heavy exotic leptons with arbitrary electric charges. We present full and exact analytical results keeping external lepton masses. As a by product, we perform numerical comparisons between exact results and approximate ones where the external lepton masses are neglected. As expected, we found that branching fractions can reach the current experimental limits if mixings and mass differences of the exotic leptons are large enough. We also found unexpectedly that, depending on the parameter values, there can be huge destructive interference between the gauge and Higgs contributions when the gauge bosons connecting the Standard Model leptons to the exotic leptons are light enough. This mechanism should be taken into account when using experimental constraints on the branching fractions to exclude the parameter space of the model.
ISSN:1434-6044
1434-6052