Low-energy lepton physics in the MRSSM: $(g-2)_\mu$, $\mu \to e\gamma$ and $\mu\to e$ 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 $(g-2)_\mu$, $\mu \to e \gamma$, and $\mu \to e$ 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 $\tan\beta$ enhancements; however we find smaller enhancements governed by MRSSM-specific R-Higgsino couplings $\lambda_d$ and $\Lambda_d$. 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 $\lambda_d$, $\Lambda_d$. In this parameter space there is a correlation between all three considered observables. In the parameter region with small $(g-2)_\mu$ the SUSY masses can be larger and the correlation between $\mu\to e\gamma$ and $\mu\to e$ conversion is weak. Therefore already COMET Phase 1 has a promising sensitivity to the MRSSM.