Mass-degenerate Higgs bosons near 125\xa0GeV in the NMSSM under current experimental constraints

Liangliang Shang,Pengqiang Sun,Zhaoxia Heng,Bingfang Yang,Yangle He

doi:10.1140/epjc/s10052-020-8132-2

Abstract

The observed Higgs signal at the Large Hadron Collider (LHC) may be derived from the two mass-degenerate resonances. We investigate this scenario in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) in which both the two lightest CP-even Higgs bosons have masses around 125 GeV. We perform a comprehensive scan over the parameters in the NMSSM considering the current experimental constraints, especially the constraints from dark matter direct detection. The surviving samples are featured with relatively small mu and large tan beta . The samples with large deviation of double ratios have large mixing between doublet field and singlet field.

Highlights

The discovery of Higgs boson with mass about 125 GeV by ATLAS and CMS collaborations [1,2] in 2012 stands for the beginning of a new era for high-energy physics
The Higgs signal near 125 GeV observed at the Large Hadron Collider (LHC) may come from the contributions of two or more nearly mass-degenerate neutral Higgs bosons, and the Higgs resonances cannot be individually resolved by experiment
Some studies have been done in the scenario with mass-degenerate Higgs states in the two-Higgsdoublet model (2HDM) [6,7] and Next-to-Minimal Supersymmetric Standard Model (NMSSM) [8,9,10,11,12,13]

Summary

Introduction

The discovery of Higgs boson with mass about 125 GeV by ATLAS and CMS collaborations [1,2] in 2012 stands for the beginning of a new era for high-energy physics. The Higgs signal near 125 GeV observed at the LHC may come from the contributions of two or more nearly mass-degenerate neutral Higgs bosons, and the Higgs resonances cannot be individually resolved by experiment. For larger values of λ and smaller tan β, the positive contribution is substantial and large radiative correction to the Higgs boson mass is unnecessary and the little hierarchy problem can be avoidable. Considering the current experimental constraints, especially the constraints from the latest Dark Matter (DM) direct detection, we aim to study this scenario with two nearly mass-degenerate CP even Higgs bosons in the NMSSM, i.e. the observed Higgs signal at the LHC may be due to the superposition of this two resonances.

Basics of the NMSSM

Scan strategies and constraints on the parameter space of NMSSM

Searching for two mass-degenerate Higgs bosons near 125 GeV

Summary