Leptonicg−2moments,CPphases, and the Higgs boson mass constraint

Abstract

Higgs boson mass measurement at ∼ 125 GeV points to a high scale for SUSY specifically the scalar masses. If all the scalars are heavy, supersymmetric contribution to the leptonic g − 2 moments will be significantly reduced. On the other hand the Brookhaven experiment indicates a ∼ 3σ deviation from the standard model prediction. Here we analyze the leptonic g − 2 moments in an extended MSSM model with inclusion of a vector like leptonic generation which brings in new sources of CP violation. In this work we consider the contributions to the leptonic g − 2 momentsarising from the exchange of charginos and neutralinos, sleptons and mirror sleptons, and from the exchange of W and Z bosons and of leptons and mirror leptons. We focus specifically on the g − 2 moments for the muon and the electron where sensitive measurements exist. Here it is shown that one can get consistency with the current data on g − 2 under the Higgs boson mass constraint. Dependence of the moments on CP phases from the extended sector are analyzed and it is shown that they are sensitively dependent on the phases from the new sector. It is shown that the corrections to the leptonic moments arising from the extended MSSM sector will be non-vanishing even if the SUSY scale extends into the PeV region. which is about a three sigma deviation from the standard model prediction. Similarly for the electron the experimental determination of g e − 2 is very accurate and the uncertainty is rather small, i.e., one has [4] ∆a e = a This result relies on a QED calculation up to four loops. Thus along with Eq. (1), Eq. (2) also acts as a constraint on the standard model extensions. Supersymmetric theories with low weak scale mass can make corrections to g µ − 2which could be as large as the standard model electroweak corrections and even larger and have strong CP phase dependence [5][6][7] (for early work see [8]). These arise largely from the chargino and sneutrino exchange diagram with the neutralino and smuon exchange diagram making a relatively small contribution. However, if the scalar masses are large, the supersymmetric exchange contributions will be small due to the largeness of the sneutrino and the smuon masses.In this work we give an analysis of the g − 2 for the muon and for the electron in an extended MSSM model with a vector like leptonic generation. We note that vector like multiplets are anomaly free and they appear in a variety of settings which include grand unified models, strings and D brane models [9][10][11][12][13]. Further, it is known that g − 2 has a sharp dependence on CP phases [5][6][7]. For this reason we investigate also the dependence of the muon and the electron g − 2 on the CP phases in the extended MSSM model. Here we are particularly interested in the dependence on the CP phases that arise from the new sector involving vector like leptons. We note that the CP phases are constrained in this case by the electric dipole moment of the electron which currently has the value |d e | < 8.7 × 10 −29ecm [34] while the upper...

Muon g − 2 and related phenomenology in constrained vector-like extensions of the MSSM

“…As an alternative, one can resolve the (g − 2) µ discrepancy by extending the particle content of the MSSM with vector-like (VL) matter, as investigated, e.g., in [29][30][31][32][33][34][35][36][37]. The introduction of VL superfields in the superpotential brings along extra degrees of freedom without spoiling the successful unification of gauge interactions at the GUT scale [38].…”

Dark matter in U(1) extensions of the MSSM with gauge kinetic mixing

“…There have been attempts to resolve these tensions, see for example [9][10][11] and references therein. In this paper, we consider U(1) ′ extensions of the MSSM (UMSSM) that can also improve the situation [12][13][14][15][16].…”

Impact of LHC data on muon g−2 solutions in a vectorlike extension of the constrained MSSM

“…There have also been alternative solutions as for example, adding vector-like (VL) matter to MSSM which has been studied in Refs. [23][24][25][26][27][28][29][30][31][32]. The presence of new VL sector gives extra contribution to (g − 2) µ by introducing new sources of smuon mixing and new Yukawa couplings [32].…”

“…The presence of new VL sector gives extra contribution to (g − 2) µ by introducing new sources of smuon mixing and new Yukawa couplings [32]. Apart from (g − 2) µ , it has been shown that VL colored sparticles provide extra contributions to Higgs mass [33][34][35][36][37][38] and several phenomenological analyses have addressed the extra VL matter in the context of various long-standing theoretical issues related to beyond SM physics [23][24][25][26][27][28][29][30][31][32].…”