Non-Standard Higgs Decays in U(1) Extensions of the MSSM

TL;DR

This paper explores the possibility of the 125 GeV Higgs boson decaying into light pseudoscalars within U(1) extended MSSM models, which could significantly alter Higgs decay signatures and phenomenology.

Contribution

It introduces a mechanism in U(1) extensions of the MSSM that allows for Higgs decays into light pseudoscalars, expanding the understanding of Higgs phenomenology in these models.

Findings

Higgs can decay into light pseudoscalars with non-negligible branching ratios

The model predicts a heavy Z' boson with mass much larger than the SUSY breaking scale

Exact custodial symmetry suppresses flavor-changing and baryon/lepton number violating processes

Abstract

In U(1) extensions of the Minimal Supersymmetric extension of the Standard Model there is a simple mechanism that leads to a heavy Z' boson with a mass which is substantially larger than the supersymmetry breaking scale. This mechanism may also result in a pseudoscalar state that is light enough for decays of the 125 GeV Standard Model-like Higgs boson into a pair of such pseudoscalars to be kinematically allowed. We study these decays within E6 inspired supersymmetric models with an exact custodial symmetry that forbids tree-level flavor-changing transitions and the most dangerous baryon and lepton number violating operators. We argue that the branching ratio of the lightest Higgs boson decays into a pair of the light pseudoscalar states may not be negligibly small.