# Revealing mass-degenerate states in Higgs boson signals

## TL;DR

This paper explores the possibility that the observed Higgs signals are due to two nearly identical scalar states, analyzing their couplings and how they could be distinguished from a single Higgs in experiments.

## Contribution

It introduces a parameterization of Higgs signal strengths in a quasi-degenerate scenario within the NMSSM, aiding experimental distinction from the Standard Model.

## Key findings

- Combined Higgs signal strengths differ from SM predictions in specific decay channels.
- Two parameters effectively describe the quasi-degenerate Higgs scenario.
- Experimental strategies can distinguish single from double Higgs states.

## Abstract

The observed Higgs boson signals to-date could be due to having two quasi-degenerate 125 GeV scalar states in Nature. This kind of scenario tallies well with the predictions from the Next-to-Minimal Supersymmetric Standard Model (NMSSM). We have analysed the phenomenological NMSSM Higgs boson couplings and derived a parameterization of the signal strengths within the two quasi-degenerate framework. With essentially two parameters, it is shown that the combined strengths of the two quasi-degenerate Higgs states in the leptonic (and b-quark) decay channels depart from the Standard Model values in the opposite direction to those in the vector boson channels. We identify experimental measurements for distinguishing a single from a double Higgs scenarios. The proposed parameterization can be used for benchmarking studies towards establishing the status of quasi-degenerate Higgs scenarios.