On the role of leptonic CPV phases in cLFV observables

Abada, Asmâa; Kriewald, J.; Teixeira, Ana

doi:10.1140/epjc/s10052-021-09754-w

Cited by 24 publications

(20 citation statements)

References 95 publications

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“…Several LNV processes (including neutrinoless double beta decays, or (semi)leptonic meson decays) are known to exhibit a strong dependence on leptonic CPV phases [5]. In [6], a thorough study of the effects of Dirac and Majorana phases on leptonic cLFV transitions and decays was carried, and in what follows we highlight the most relevant results.…”

Section: Motivationmentioning

confidence: 98%

“…In order to illustrate the role of CPV phases regarding cLFV observables, consider the case of 𝜇 → 𝑒𝛾 decays, mediated by 𝑊 bosons and both light and heavy neutrinos. The associated branching fraction (see [6] and references therein) is given by…”

Section: The Role Of Phases: First Approachmentioning

confidence: 99%

“…in which 𝐺 𝛾 (𝑥 𝑖 ), with 𝑥 𝑖 = 𝑚 2 𝑁 𝑖 /𝑚 2 𝑊 , is a dimensionless loop function (see [6]). In the limit 𝑚 4 ≈ 𝑚 5 and for sin 𝜃 𝛼4 ≈ sin 𝜃 𝛼5 ≪ 1 the form factor is given by…”

Section: The Role Of Phases: First Approachmentioning

confidence: 99%

“…1We consider constraints from electroweak precision observables lepton universality tests, neutrinoless double beta decays, and finally perturbative unitarity constraints (Γ 𝑁 4,5 /𝑚 4,5 ≤ 1/2); for a detailed description, see[6].…”

mentioning

confidence: 99%

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The role of leptonic CPV phases in cLFV observables

Kriewald¹,

Abada²,

Teixeira³

2022

Proceedings of the 22nd International Workshop on Neutrinos From Accelerators — PoS(NuFact2021)

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In models where the Standard Model is extended by Majorana fermions, interference effects due to the presence of CP violating phases have been shown to play a crucial role in lepton number violating processes. However, important effects can also arise in lepton number conserving, but charged lepton flavour violating (cLFV) transitions and decays. Here we show that the presence of CP violating (Dirac and Majorana) phases can have a striking impact for the predicted rates of cLFV observables. We explore the interference effects in several cLFV observables, carrying for the first time a thorough analysis of the different observables and the implications for future observation. We discuss how the presence of leptonic CP violating phases might lead to a loss of correlation between observables (typically present in simple SM extensions via heavy sterile fermions), or even to the suppression of certain channels; these effects can be interpreted as suggestive of non-vanishing phases.

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Section: Motivationmentioning

confidence: 98%

Section: The Role Of Phases: First Approachmentioning

confidence: 99%

Section: The Role Of Phases: First Approachmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

The role of leptonic CPV phases in cLFV observables

Kriewald¹,

Abada²,

Teixeira³

2022

Proceedings of the 22nd International Workshop on Neutrinos From Accelerators — PoS(NuFact2021)

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“…Here we examine the impact of leptonic CP phases on cLFV processes for our class of seesaw models. It was argued in [40] that the existence of non-zero leptonic CP phases may have a substantive impact on the rate of cLFV processes through the interference terms involving the mixing B α . Following a procedure similar to [40], we write the elements of B iα as a magnitude s iα and a phase ε iα .…”

Section: Non-zero Leptonic Cp Phases In Clfv Processesmentioning

confidence: 99%

Tri-resonant leptogenesis in a seesaw extension of the Standard Model

Silva

Karamitros

et al. 2022

J. High Energ. Phys.

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We study a class of leptogenesis models where the light neutrinos acquire their observed small masses by a symmetry-motivated construction. This class of models may naturally include three nearly degenerate heavy Majorana neutrinos that can strongly mix with one another and have mass differences comparable to their decay widths. We find that such a tri-resonant heavy neutrino system can lead to leptonic CP asymmetries which are further enhanced than those obtained in the usual bi-resonant approximation. Moreover, we solve the Boltzmann equations by paying special attention to the temperature dependence of the relativistic degrees of freedom of the plasma. The latter results in significant corrections to the evolution equations for the heavy neutrinos and the lepton asymmetry that have been previously ignored in the literature. We show the importance of these corrections to accurately describe the dynamical evolution of the baryon-to-photon ratio ηB for heavy neutrino masses at and below 100 GeV, and demonstrate that successful leptogenesis at lower masses can be significantly affected by the variation of the relativistic degrees of freedom. The parameter space for the leptogenesis model is discussed, and it could be probed in future experimental facilities searching for charged lepton flavour violation and heavy neutrinos in future Z-boson factories.

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Three-loop inverse scotogenic seesaw models

Abada,

Bernal,

Cárcamo Hernández

et al. 2024

J. High Energ. Phys.

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We propose a class of models providing an explanation of the origin of light neutrino masses, the baryon asymmetry of the Universe via leptogenesis and offering viable dark matter candidates. In these models the Majorana masses of the active neutrino are generated by the inverse seesaw mechanism with the lepton number violating right-handed Majorana neutrino masses μ arising at three loops. The latter is ensured by the preserved discrete symmetries, which also guarantee the stability of the dark matter candidate. We focus on one of these models and perform a detailed analysis of the phenomenology of its leptonic sector. The model can successfully accommodate baryogenesis through leptogenesis in both weak and strong washout regimes. The lightest heavy fermion turns out to be a viable dark matter candidate, provided that the entries of the Majorana submatrix μ are in the keV to MeV range. The solutions are consistent with the experimental constraints, accommodating both mass orderings for active neutrinos, in particular charged-lepton flavor violating decays μ → eγ, μ → eee, and the electron-muon conversion processes get sizable rates within future sensitivity reach.

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On the role of leptonic CPV phases in cLFV observables

Cited by 24 publications

References 95 publications

The role of leptonic CPV phases in cLFV observables

The role of leptonic CPV phases in cLFV observables

Tri-resonant leptogenesis in a seesaw extension of the Standard Model

Three-loop inverse scotogenic seesaw models

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