Probing degenerate heavy Higgs bosons in NMSSM with vector-like particles

TL;DR

This paper explores the properties and detection prospects of degenerate heavy Higgs bosons in the NMSSM extended with vector-like particles, considering current experimental constraints and proposing future search strategies.

Contribution

It introduces a model extension with vector-like particles in the NMSSM and analyzes the resulting Higgs boson phenomenology under experimental constraints.

Findings

Degenerate heavy Higgs bosons can decay invisibly into dark matter candidates.

Current LHC data tightly constrains the parameter space of these models.

Monojet searches at future LHC runs can probe these Higgs bosons.

Abstract

In this work, we investigate the degenerate heavy Higgs bosons in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) by introducing vector-like particles. Such an extension is well motivated from the top-down view since some grand unified theories usually predict the existence of singlet scalars and vector-like particles at weak scale. Under the constraints from the LHC and dark matter experiments, we find that (1) the null results of searching for high mass resonances have tightly constrained the parameter space; (2) two degenerate heavy singlet Higgs bosons $h_2$ and $a_1$ can sizably decay to $\chi^0_1\chi^0_1$ invisibly. Therefore, search for the monojet events through the process $gg \to h_2 / a_1 (\to \chi^0_1 \chi^0_1) j$ may further test our scenario at the future LHC.