Low-energy lepton physics in the MRSSM: (g − 2)μ, μ→eγ and μ→e conversion

Abstract

Low-energy lepton observables are discussed in the Minimal R-symmetric Supersymmetric Standard Model. We present comprehensive numerical analyses and the analytic one-loop results for (g − 2) µ , µ → eγ, and µ → e conversion. The interplay between the three observables is investigated as well as the parameter regions with large g − 2. A striking difference to the MSSM is the absence of tan β enhancements; however we find smaller enhancements governed by MRSSM-specific R-Higgsino couplings λ d and Λ d. As a result we find significant contributions to g − 2 only in a small parameter space with several SUSY masses below 200 GeV, compressed spectra and large λ d , Λ d. In this parameter space there is a correlation between all three considered observables. In the parameter region with small (g − 2) µ the SUSY masses can be larger and the correlation between µ → eγ and µ → e conversion is weak. Therefore already COMET Phase 1 has a promising sensitivity to the MRSSM.

Muon conversion to an electron in nuclei in the minimal R-symmetric supersymmetric standard model

“…The predictions for CRðμ − e; nucleusÞ in nuclei are not sensitive to tan β or m A and take values in a narrow region. This is a striking difference to some SUSY models [28,29,31,43]. Due to the existence of the transition from d-Higgsino to u-Higgsino in the MSSM, which is governed by the μ term, the well-known tan β enhancement is possible.…”

“…More information about the ρ-charginos can be found in Refs. [39,41,43,53]. In MRSSM the LFV decays mainly originate from the potential misalignment in sleptons mass matrices.…”

“…Additional superfieldsŜ,T, andÔ are introduced to yield Dirac mass terms of gauginos. Studies on phenomenology in the MRSSM can be found in the literature [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55]. Similar to MSSM, the off-diagonal entries δ ij in slepton mass matrices m 2 l and m 2 r dominate the LFV process μ-e conversion.…”

Confronting the coloured sector of the MRSSM with LHC data

“…It constitutes a potential solution to the SUSY flavour problem; the R-symmetry effectively suppresses flavour-violating contributions in the quark/lepton sectors, thus allowing large flavour mixing and rather light masses in the squark/slepton sectors [1,2]. In a series of papers [3][4][5][6][7][8], MRSSM electroweak phenomenology has been found to be rich and successful. The model can accommodate the observed Higgs boson mass for stop masses in the 1 TeV range, it is compatible with electroweak precision observables, and it can explain the observed dark matter relic density without conflict with direct dark matter searches and it can lead to interesting signals in muon g-2 and lepton flavour violation experiment.…”

Confronting the Coloured Sector of the MRSSM with LHC Data

“…It constitutes a potential solution to the SUSY flavour problem; the R-symmetry effectively suppresses flavour-violating contributions in the quark/lepton sectors, thus allowing large flavour mixing and rather light masses in the squark/slepton sectors [1,3]. In a series of papers [4][5][6][7][8], MRSSM electroweak phenomenology has been found to be rich and successful. The model can accommodate the observed Higgs boson mass for stop masses in the 1 TeV range, it is compatible with electroweak precision observables, and it can explain the observed dark matter relic density without conflict with JHEP09(2019)120 direct dark matter searches and it can lead to interesting signals in muon g-2 and lepton flavour violation experiment.…”