Hefty MSSM-like light Higgs in extended gauge models

TL;DR

This paper explores how extending the gauge symmetry in models similar to the MSSM can significantly increase the mass of the lightest Higgs boson, potentially reaching around 140 GeV, surpassing the MSSM limit.

Contribution

It demonstrates that extending the gauge sector in MSSM-like models can raise the Higgs mass beyond the traditional MSSM bounds, especially with a specific U(1)_R x U(1)_B-L extension.

Findings

Higgs mass can reach ~140 GeV in extended gauge models

Extension involves a low-scale U(1)_R x U(1)_B-L symmetry

Neutrino masses can be incorporated via inverse seesaw

Abstract

It is well known that in the MSSM the lightest neutral Higgs h^0 must be, at the tree level, lighter than the Z boson and that the loop corrections shift this stringent upper bound up to about 130 GeV. Extending the MSSM gauge group in a suitable way, the new Higgs sector dynamics can push the tree-level mass of h^0 well above the tree-level MSSM limit if it couples to the new gauge sector. This effect is further pronounced at the loop level and h^0 masses in the 140 GeV ballpark can be reached easily. We exemplify this for a sample setting with a low-scale U(1)_R x U(1)_B-L gauge symmetry in which neutrino masses can be implemented via the inverse seesaw mechanism.