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

Abstract

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.

Lepton Flavor Violating Higgs Boson Decays in Supersymmetric High Scale Seesaw Models

“…2 contain the same neutralino and chargino couplings that appear in the cLFV decays of Fig. 1 with very strong experimental bounds [42,43]. LFV Higgs interaction are enhanced in the non decoupling regime (M A > ∼ M Z ) [71][72][73][74] leading to larger values for BR(h → µ ± τ ∓ ), like the ones found in Refs.…”

“…One common feature among these models is that the LFV effects in these models are generated by non diagonal entries (as explained above for the Type I see-saw mechanism) in the slepton mass matrix. These off-diagonal entries in the slepton mass matrix not only predict sizeable rates for the cLFV processes but can also results in the LFV decays of the Higgs boson [37][38][39][40][41][42][43]. While supersymmetric high scale see-saw models successfully describe the neutrino masses and mixing and predict sizeable rates for the cLFV processes, it is yet to be seen if they can also explain the CMS reported excess, which precisely is the aim of this work.…”

Search for lepton flavour violating decays of the Higgs boson to μτ and eτ in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

“…These decays are forbidden in the SM but occur in many new physics scenarios. These include supersymmetric [5][6][7][8][9][10][11][12][13], composite Higgs [14,15], or Randall-Sundrum models [16][17][18], SM extensions with more than one Higgs boson doublet [19,20] or with flavour symmetries [21], and many other scenarios [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. The presence of LFV Higgs boson couplings would allow τ → µ and τ → e to proceed via a virtual Higgs boson [37,38].…”

Muon $$g-2$$ g - 2 through a flavor structure on soft SUSY terms

“…The results in the literature are usually obtained using the MIA approximation, however, there are some schemes where the work is done in the physical basis (e.g. [41]). The difference with the MIA method is not only the change in basis, but the restriction that is imposed a priori that some elements in the mass matrix are considered small compared to the diagonal ones.…”

“…There is also a more general phenomenological work considering non-diagonal LL, RR and RL blocks of sfermion mass matrices which are parameterized as a sfermion mass product and a free parameter for each matrix element in order to do a numerical evaluation of the processes in the mass basis [39], having all the elements of the 6 × 6 sfermion mass matrix as parameters that might be constrained by the LFV processes. Recent analysis of these general FV contributions are done in [40,41]. This general sfermion mass matrix, although complete, implies a considerable increase in the number of parameters.…”