Diphoton Rate of the Standard-Model-Like Higgs Boson in the Extra U(1) Extended MSSM

TL;DR

This paper explores how an extended MSSM with an extra U(1) gauge symmetry can explain the observed excess in Higgs boson diphoton decay rate at the LHC, by analyzing parameter space and Higgs mixing effects.

Contribution

It demonstrates that the SM-like Higgs in the extended MSSM can have an enhanced diphoton rate through specific parameter choices and Higgs mixing, consistent with LHC observations.

Findings

SM-like Higgs is mostly the lightest CP-even Higgs

Strong mixing with a singlet-like second lightest Higgs

Enhanced diphoton rate consistent with LHC data

Abstract

Motivated by the excess in the diphoton production rate of the Higgs boson at the Large Hadron Collider (LHC), we investigate the possibility that one of the CP-even Higgs bosons of the extra U(1) extended minimal supersymmetric standard model can give a consistent result. We scan the parameter space for a standard-model-like Higgs boson such that the mass is in the range of 124-127 GeV and the production rate \sigma xB of the WW*, ZZ* modes are consistent with the standard model (SM) values while that of \gamma\gamma is enhanced relative to the SM value. We find that the SM-like Higgs boson is mostly the lightest CP-even Higgs boson and it has a strong mixing with the second lightest one, which is largely singlet-like. The implications on Z\gamma production rate and properties of the other Higgs bosons are also studied.