What if bb does not dominate the decay of the Higgs-like boson?

TL;DR

This paper explores a scenario where the dominant decay mode of a Higgs-like boson at 126 GeV is not $bar{b}$, proposing a non-decoupling MSSM Higgs decay into lighter Higgses to explain suppressed $bar{b}$ and $ au^+ au^-$ signals, with implications for LHC searches.

Contribution

It introduces a highly fine-tuned MSSM scenario where the Higgs decay into lighter Higgs pairs explains suppressed decay channels, providing a new perspective on Higgs phenomenology.

Findings

Suppressed $bar{b}$ and $ au^+ au^-$ modes suggest an alternative decay channel.

The decay $H o hh$ can fit the observed Higgs signals in a non-decoupling MSSM scenario.

Potential for discovering $H o hh$ at the LHC in highly fine-tuned parameter space.

Abstract

The dominant decay mode of standard model Higgs at 126 GeV $b\bar{b}$ suffers from severe SM background at the LHC even in associated productions $Wh_{\rm SM}$ or $Z h_{\rm SM}$. The precision measurement of BR($\phi\to b\bar{b})$ requires more data to reduce its large error bar. We investigate the possibility of this channel with largest uncertainty not dominating the decay of Higgs-like boson discovered at the LHC. In such scenarios, the Higgs signal shows highly suppressed $b\bar{b}$, slightly reduced $\tau^{+}\tau^{-}$ and moderately enhanced gauge bosons comparing with the SM predictions. The model requires two different sources of electroweak symmetry breaking and radiative correction to $m_{b}$ strongly enhanced. However, large reduction in $b\bar{b}$ usually results large enhancement in $\tau^{+}\tau^{-}$ mode in particular. The reduction of $\tau^{+}\tau^{-}$ therefore implies that a new decay mode is inevitable. We find that a non-decoupling MSSM Higgs decay into lighter Higgs $H\to hh$ may fit the signature. Here, MSSM $H$ is identified as the 126 GeV resonance while $h$ is below $M_{H}/2$ and can evade the direct search bound at LEPII and Tevatron. Large $PQ$ and $R$ symmetry breaking effects mediated by strong interaction can strongly enhance radiative corrections in $m_b$. However, the scenario can only be realized in highly fine-tuned parameter region where $G_{Hhh}$ is tiny. Nevertheless, we discuss the discovery potential of this highly fine-tuned $H\to hh$ at the LHC.