The MSSM Higgs sector at a high $M_{SUSY}$: reopening the low tan$\beta$ regime and heavy Higgs searches

TL;DR

This paper explores the MSSM Higgs sector at high SUSY-breaking scales, showing that high $M_S$ values reopen the low tan$eta$ regime and influence heavy Higgs searches at the LHC.

Contribution

It demonstrates that high $M_S$ allows a simplified two-parameter description of the Higgs sector and reopens the low tan$eta$ region, impacting heavy Higgs search strategies.

Findings

High $M_S$ correlates with the measured $M_h$, simplifying the Higgs sector analysis.

Reopening of the low tan$eta$ region under high $M_S$ assumptions.

Potential LHC search channels for heavy Higgs states in various decay modes.

Abstract

One of the main implications of the LHC discovery of a Higgs boson with a mass $M_h \approx 126$ GeV is that the scale of supersymmetry-breaking in the Minimal Supersymmetric Standard Model (MSSM) might be rather high, $M_S \gg M_Z$. In this paper, we consider the high $M_S$ regime and study the spectrum of the extended Higgs sector of the MSSM, including the LHC constraints on the mass and the rates of the observed light $h$ state. In particular, we show that in a simplified model that approximates the important radiative corrections, the unknown scale $M_S$ (and some other leading SUSY parameters) can be traded against the measured value of $M_h$. One would be then essentially left with only two free parameters to describe the Higgs sector, tan$\beta$ and the pseudoscalar Higgs mass $M_A$, even at higher orders. The main phenomenological consequence of these high $M_S$ values is to reopen the low tan$\beta$ region, tan$\beta \lsim 3-5$, which was for a long time buried under the LEP constraint on the lightest $h$ mass when a low SUSY scale was assumed. We show that, in this case, the heavier MSSM neutral $H/A$ and charged $H^\pm$ states can be searched for in a variety of interesting final states such as decays into gauge and lighter Higgs bosons (in pairs on in mixed states) and decays into heavy top quarks. Examples of sensitivity on the $[tan\beta, M_A]$ parameter space at the LHC in these channels are given.