# The invisible decay of Higgs boson in the context of a thermal and non-thermal relic in MSSM

## TL;DR

This paper investigates the decay of the Higgs boson into light neutralinos within the MSSM, exploring collider and astrophysical signals to understand dark matter relic density and cosmology implications.

## Contribution

It analyzes the parameter space for light neutralinos in MSSM, considering both thermal and non-thermal relic scenarios, and assesses combined collider and astrophysical measurements for dark matter characterization.

## Key findings

- Invisible Higgs decay can probe light neutralinos at ILC.
- Astrophysical experiments can complement collider data.
- Different relic density scenarios have distinct experimental signatures.

## Abstract

We study the decay of 125 GeV Higgs boson to light LSP neutralino in the phenomenological minimal supersymmetric standard model in the context of collider searches and astrophysical experiments. We consider the parameter space for light neutralinos that can be probed via the invisible Higgs decays and higgsino searches at the ILC. We consider the cases where the light neutralino is compatible with the observed relic density or where the thermal relic is over-abundant, pointing to non-standard cosmology. In the former case, when the neutralino properties give rise to under-abundant relic density, the correct amount of relic abundance is assumed to be guaranteed by either additional DM particles or by non-thermal cosmology. We contrast these different cases. We assess what astrophysical measurements can be made, in addition to the measurements made at the ILC, which can provide a clue to the nature of the light neutralino. We find that a number of experiments, including Xenon-nT, PICO-250, LZ in conjunction with measurements made at the ILC on invisible Higgs width can pin down the nature of this neutralino, along with its cosmological implications. Additionally, we also point out potential LHC signatures that could be complementary in this region of parameter space.