Searches for Lepton Flavor Violation in the Decays<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>e</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mi>γ</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>τ</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>μ</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mi>γ</mml:mi

Abstract:We investigate the radiative generation of lepton masses and mixing angles in the Standard Model extended by one right-handed neutrino and one extra Higgs doublet. We assume approximate rank-1 Yukawa couplings at a high energy scale and we calculate the one loop corrected charged lepton and neutrino mass matrices at the low energy scale. We find that quantum effects generate, for typical high energy parameters, a hierarchy between the muon and the tau mass, a hierarchy between the solar and the atmospheric mass splittings, and a pattern of leptonic mixing angles in qualitative agreement with experiments.

Section: Introductionsupporting

confidence: 51%

Lepton parameters in the see-saw model extended by one extra Higgs doublet

Ibarra

Solaguren-Beascoa

2014

“…From figures 6-9 we learn that the only delta that can lead us to phenomenologically interesting LFVHD rates is δ [54]. The shaded blue area represents the 95% C.L.…”

Section: Jhep03(2016)055mentioning

confidence: 99%

“…First, the contour lines of these two observables in the [m SUSY , tan β] plane are displayed in figure 10, within the Equal masses scenario with m A = 800 GeV. In both contour plots, the shaded red area is excluded by the current experimental upper limit for τ → µγ channel, BR(τ → µγ) < 4.4×10 −8 [54], and the shaded blue area represents the 95% C.L. excluded regions by the negative searches by ATLAS and CMS for neutral MSSM Higgs bosons decaying to a pair of τ leptons [55,56].…”

Section: Jhep03(2016)055mentioning

confidence: 99%

“…In this work we will also include a numerical computation of the LFVHD rates with the MIA for the case of most interest at present, h, H, A → τμ, which will be systematically compared with the full one-loop results to be able to conclude on the goodness of this approximation, the MIA, and its range of applicability. Finally we will conclude with simple analytic formulas for the useful LFV effective vertices, V eff Hxτ µ , and with a numerical estimate of the maximum expected BR(h, H, A → τμ) rates that are allowed by the present experimental constraints from τ → µγ [54] and by the ATLAS and CMS searches for neutral Higgs bosons beyond the SM [55,56]. This numerical study will be performed in terms of the most relevant model parameters, emphasizing which flavor mixing parameters will be most efficiently tested at future colliders.…”

Section: Jhep03(2016)055mentioning

confidence: 99%

See 1 more Smart Citation

Analysis of the h, H, A → τμ decays induced from SUSY loops within the Mass Insertion Approximation

Arganda

Herrero

Morales

et al. 2016

In this paper we study the lepton favor violating decay channels of the neutral Higgs bosons of the Minimal Supersymmetric Standard Model into a lepton and an antilepton of different flavor. We work in the context of the most general flavor mixing scenario in the slepton sector, in contrast to the minimal flavor violation assumption more frequently used. Our analytic computation is a one-loop diagrammatic one, but in contrast to the full one-loop computation which is usually referred to the physical slepton mass basis, we use here instead the Mass Insertion Approximation (MIA) which uses the electroweak interaction slepton basis and treats perturbatively the mass insertions changing slepton flavor. By performing an expansion in powers of the external momenta in the relevant form factors, we will be able to separate explicitly in the analytic results the leading non-decoupling (constant at asymptotically large sparticle masses) and the next to leading decoupling contributions (decreasing with the sparticle masses). Our final aim is to provide a set of simple analytic formulas for the form factors and the associated effective vertices, that we think may be very useful for future phenomenological studies of the lepton flavor violating Higgs boson decays, and for their comparison with data. The accuracy of the numerical results obtained with the MIA are also analyzed and discussed here in comparison with the full one-loop results. Our most optimistic numerical estimates for the three neutral Higgs boson decays channels into τ and µ leptons, searching for their maximum rates that are allowed by present constraints from τ → µγ data and beyond Standard Model Higgs boson searches at the LHC, are also included.

“…The current upper bound on the τ → eγ process is 1.1 × 10 −7 [80], and it is rather weak compared with the one from the µ → eγ process. In figure 3, the regions excluded by τ → eγ, τ − → e − µ + µ − , and τ − → e + µ − µ − are summarized.…”

Section: Constraint From the τ → Eγ Processmentioning

confidence: 99%

Study of lepton flavor violation in flavor symmetric models for lepton sector

Kobayashi

Omura

Takayama

et al. 2015

Flavor symmetric model is one of the attractive Beyond Standard Models (BSMs) to reveal the flavor structure of the Standard Model (SM). A lot of efforts have been put into the model building and we find many kinds of flavor symmetries and setups are able to explain the observed fermion mass matrices. In this paper, we look for common predictions of physical observables among the ones in flavor symmetric models, and try to understand how to test flavor symmetry in experiments. Especially, we focus on the BSMs for leptons with extra Higgs SU(2) L doublets charged under flavor symmetry. In many flavor models for leptons, remnant symmetry is partially respected after the flavor symmetry breaking, and it controls well the Flavor Changing Neutral Currents (FCNCs) and suggests some crucial predictions against the flavor changing process, although the remnant symmetry is not respected in the full lagrangian. In fact, we see that τ − → e + µ − µ − (µ + e − e − ) and e + e − → τ + τ − (µ − µ + ) processes are the most important in the flavor models that the extra Higgs doublets belong to triplet representation of flavor symmetry. For instance, the stringent constraint from the µ → eγ process could be evaded according to the partial remnant symmetry. We also investigate the breaking effect of the remnant symmetry mediated by the Higgs scalars, and investigate the constraints from the flavor physics: the flavor violating τ and µ decays, the electric dipole moments, and the muon anomalous magnetic moment. We also discuss the correlation between FCNCs and nonzero θ 13 , and point out the physical observables in the charged lepton sector to test the BSMs for the neutrino mixing.