Large BR(h -> tau mu) in Supersymmetric Models

TL;DR

This paper investigates the potential for large lepton flavor violating Higgs decays, specifically h -> tau mu, within various supersymmetric models, highlighting that only the BLSSM-IS can naturally accommodate the observed decay rates without conflicting with experimental constraints.

Contribution

It demonstrates that the BLSSM-IS model uniquely allows for sizable BR(h -> tau mu) consistent with experimental bounds, unlike MSSM and SSM.

Findings

MSSM cannot enhance BR(h -> tau mu) without violating tau -> mu gamma constraints.

In SSM, BR(h -> tau mu) is limited to ~10^-10, far below experimental hints.

BLSSM-IS can explain observed BR(h -> tau mu) without violating LFV bounds.

Abstract

We analyze the Lepton Flavor Violating (LFV) Higgs decay h -> tau mu in three supersymmetric models: Minimal Supersymmetric Standard Model (MSSM), Supersymmetric Seesaw Model (SSM), and Supersymmetric B-L model with Inverse Seesaw (BLSSM-IS). We show that in generic MSSM, with non-universal slepton masses and/or trilinear couplings, it is not possible to enhance BR(h -> tau mu) without violating the experimental bound on the BR(tau -> mu gamma). In SSM, where flavor mixing is radiatively generated, the LFV process mu -> e gamma strictly constrains the parameter space and the maximum value of BR(h -> tau mu) is of order 10^-10, which is extremely smaller than the recent results reported by the CMS and ATLAS experiments. In BLSSM-IS, with universal soft SUSY breaking terms at the grand unified scale, we emphasize that the measured values of BR(h -> tau mu) can be accommodated in a wide region of parameter space without violating LFV constraints. Thus, confirming the LFV Higgs decay results will be a clear signal of BLSSM-IS type of models. Finally, the signal of h -> tau mu in the BLSSM-IS at the LHC, which has a tiny background, is analyzed.