The 125 GeV Higgs in the NMSSM in light of LHC results and astrophysics constraints

TL;DR

This paper investigates whether the NMSSM model can explain the 125 GeV Higgs signal observed at the LHC, considering astrophysical constraints and potential unique signatures of supersymmetric particles.

Contribution

It demonstrates that the NMSSM can accommodate the Higgs signal while satisfying astrophysical dark matter constraints and proposes new search strategies for supersymmetric signatures.

Findings

NMSSM can explain the Higgs signal within astrophysical constraints

Parameter space configurations compatible with observed Higgs signal

Potential for distinguishing NMSSM Higgs from Standard Model via dedicated searches

Abstract

Recent LHC data suggest an excess in the Higgs decay channels into gamma gamma, W W and Z Z at roughly 125 GeV. The current excess in the diphoton channel is twice that expected from a Standard Model Higgs; whilst this may well change with more statistics, it is interesting to consider the implications should the result persist. Here, we assess whether the NMSSM with a neutralino dark matter candidate could explain this excess when astrophysical constraints (e.g. no overproduction of gamma rays and radio emission in the galaxy, no anomalous excess in the dark matter direct detection experiments and no dark matter overabundance) are imposed on the neutralino. This enables us to disregard unphysical regions of the parameter space even though the Higgs signal is compatible with the observed excess. The result of our analysis is that there are configurations of the parameter space which can explain the signal strength reported by the ATLAS and CMS collaborations for a Higgs mass within the required range. Should the observed signal strength finally be compatible with Standard Model expectations, it would be difficult to distinguish between the discovery of Standard Model Higgs and a SM-like Higgs from the NMSSM, unless one performs dedicated searches of very light Higgs bosons and possibly investigate peculiar signatures of supersymmetric particles. We also propose a new jets + missing E_T signal for the case where the LSP is a singlino-like neutralino.