Non-decoupling SUSY in LFV Higgs decays: a window to new physics at the LHC

TL;DR

This paper investigates non-decoupling effects of SUSY in lepton flavor violating Higgs decays, showing these rates remain significant even at high SUSY scales, and highlights potential observability at the LHC.

Contribution

It demonstrates that LFV Higgs decay rates in SUSY models do not diminish with increasing SUSY scale, providing new avenues for detecting SUSY effects at the LHC.

Findings

LFV Higgs decay rates remain constant for SUSY scales above 2 TeV.

The decay channel h → τμ is the most promising for detection.

Up to hundreds of LFV events could be observed at current LHC conditions.

Abstract

The recent discovery of a SM-like Higgs boson at the LHC, with a mass around 125-126 GeV, together with the absence of results in the direct searches for supersymmetry, is pushing the SUSY scale ($m_\text{SUSY}$) into the multi-TeV range. This discouraging situation from a low-energy SUSY point of view has its counterpart in indirect SUSY observables which present a non-decoupling behavior with $m_\text{SUSY}$. This is the case of the one-loop lepton flavor violating Higgs decay rates induced by SUSY, which are shown here to remain constant as $m_\text{SUSY}$ grows, for large $m_\text{SUSY} >$ 2 TeV values and for all classes of intergenerational mixing in the slepton sector, $LL$, $LR$, $RL$ and $RR$. In this work we focus on the LFV decays of the three neutral MSSM Higgs bosons $h$, $H$, $A \to \tau \mu$, considering the four types of slepton mixing ($\delta_{23}^{LL}$, $\delta_{23}^{LR}$, $\delta_{23}^{RL}$, $\delta_{23}^{RR}$), and show that all the three channels could be measurable at the LHC, being $h \to \tau \mu$ the most promising one, with up to about hundred of events expected with the current LHC center-of-mass energy and luminosity. The most promising predictions for the future LHC stage are also included.