Flavor violating leptonic decays of $$\tau $$ τ and $$\mu $$ μ leptons in the Standard Model with massive neutrinos
Abstract We have revisited the computations of the flavor violating leptonic decays of the $$\tau $$ τ and $$\mu $$ μ leptons into three lighter charged leptons in the Standard Model with massive neutrinos. We were driven by a claimed unnaturally large branching ratio predicted for the $$\tau ^-\rig...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2019-01-01
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| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | http://link.springer.com/article/10.1140/epjc/s10052-019-6563-4 |
| _version_ | 1818864054717906944 |
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| author | G. Hernández-Tomé G. López Castro P. Roig |
| author_facet | G. Hernández-Tomé G. López Castro P. Roig |
| author_sort | G. Hernández-Tomé |
| collection | DOAJ |
| description | Abstract We have revisited the computations of the flavor violating leptonic decays of the $$\tau $$ τ and $$\mu $$ μ leptons into three lighter charged leptons in the Standard Model with massive neutrinos. We were driven by a claimed unnaturally large branching ratio predicted for the $$\tau ^-\rightarrow \mu ^- \ell ^+ \ell ^-$$ τ-→μ-ℓ+ℓ- ($$\ell =\mu , e$$ ℓ=μ,e ) decays (Pham, Eur Phys J C 8:513 1999), which was at odds with the corresponding predictions for the $$\mu ^-\rightarrow e^- e^-e^+$$ μ-→e-e-e+ processes (Petcov, Sov J Nucl Phys 25:340 1977). In contrast with the prediction in [17], our results are strongly suppressed and in good agreement with the approximation made in Ref. [15], where masses and momenta of the external particles were neglected in order to deal with the loop integrals. However -as a result of keeping external momenta and masses in the computation of the dominant penguin and box diagrams- we even find slightly smaller branching fractions. Therefore, we confirm that any future observation of such processes would be an unambiguous manifestation of new physics beyond the Standard Model. |
| first_indexed | 2024-12-19T10:25:33Z |
| format | Article |
| id | doaj.art-576b6173c8d44cf0a9662ef1f5e6b4f4 |
| institution | Directory Open Access Journal |
| issn | 1434-6044 1434-6052 |
| language | English |
| last_indexed | 2024-12-19T10:25:33Z |
| publishDate | 2019-01-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | European Physical Journal C: Particles and Fields |
| spelling | doaj.art-576b6173c8d44cf0a9662ef1f5e6b4f42022-12-21T20:25:55ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60441434-60522019-01-0179111610.1140/epjc/s10052-019-6563-4Flavor violating leptonic decays of $$\tau $$ τ and $$\mu $$ μ leptons in the Standard Model with massive neutrinosG. Hernández-Tomé0G. López Castro1P. Roig2Departamento de Física, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico NacionalDepartamento de Física, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico NacionalDepartamento de Física, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico NacionalAbstract We have revisited the computations of the flavor violating leptonic decays of the $$\tau $$ τ and $$\mu $$ μ leptons into three lighter charged leptons in the Standard Model with massive neutrinos. We were driven by a claimed unnaturally large branching ratio predicted for the $$\tau ^-\rightarrow \mu ^- \ell ^+ \ell ^-$$ τ-→μ-ℓ+ℓ- ($$\ell =\mu , e$$ ℓ=μ,e ) decays (Pham, Eur Phys J C 8:513 1999), which was at odds with the corresponding predictions for the $$\mu ^-\rightarrow e^- e^-e^+$$ μ-→e-e-e+ processes (Petcov, Sov J Nucl Phys 25:340 1977). In contrast with the prediction in [17], our results are strongly suppressed and in good agreement with the approximation made in Ref. [15], where masses and momenta of the external particles were neglected in order to deal with the loop integrals. However -as a result of keeping external momenta and masses in the computation of the dominant penguin and box diagrams- we even find slightly smaller branching fractions. Therefore, we confirm that any future observation of such processes would be an unambiguous manifestation of new physics beyond the Standard Model.http://link.springer.com/article/10.1140/epjc/s10052-019-6563-4 |
| spellingShingle | G. Hernández-Tomé G. López Castro P. Roig Flavor violating leptonic decays of $$\tau $$ τ and $$\mu $$ μ leptons in the Standard Model with massive neutrinos European Physical Journal C: Particles and Fields |
| title | Flavor violating leptonic decays of $$\tau $$ τ and $$\mu $$ μ leptons in the Standard Model with massive neutrinos |
| title_full | Flavor violating leptonic decays of $$\tau $$ τ and $$\mu $$ μ leptons in the Standard Model with massive neutrinos |
| title_fullStr | Flavor violating leptonic decays of $$\tau $$ τ and $$\mu $$ μ leptons in the Standard Model with massive neutrinos |
| title_full_unstemmed | Flavor violating leptonic decays of $$\tau $$ τ and $$\mu $$ μ leptons in the Standard Model with massive neutrinos |
| title_short | Flavor violating leptonic decays of $$\tau $$ τ and $$\mu $$ μ leptons in the Standard Model with massive neutrinos |
| title_sort | flavor violating leptonic decays of tau τ and mu μ leptons in the standard model with massive neutrinos |
| url | http://link.springer.com/article/10.1140/epjc/s10052-019-6563-4 |
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