Higgs Masses in the Four Generation MSSM

TL;DR

This paper explores how adding a fourth fermion generation to the MSSM significantly raises the upper bound on the lightest Higgs mass and alters the mass relationships among Higgs particles, impacting search strategies.

Contribution

It demonstrates that in the four-generation MSSM, the lightest Higgs mass upper bound increases to about 400 GeV and the charged Higgs can be much heavier than the pseudoscalar, unlike in the three-generation case.

Findings

Upper bound on lightest Higgs mass increases to ~400 GeV

Charged Higgs can be much heavier than pseudoscalar Higgs

Higgs mass relationships differ significantly from three-generation MSSM

Abstract

In the Minimal Supersymmetric Standard Model (MSSM) with three generations of fermions, there is a stringent upper bound on the mass of the lightest neutral Higgs h, and the mass of the charged Higgs H^+, must be close (within tens of GeV) to the heavier neutral Higgs, H, and the pseudoscalar Higgs A. In this Brief Report, we show that in the four generation MSSM, the upper bound on the h mass is much higher, as high as 400 GeV, and H^+ is generally much heavier than the A, allowing the H^+ -> A W^+ decay, potentially changing search strategies for both the charged Higgs and the pseudoscalar. The H mass, on the other hand, remains within tens of GeV of the charged Higgs mass.