LHC constraints on light neutralino dark matter in the MSSM

TL;DR

This paper investigates the parameter space of the MSSM allowing light neutralino dark matter, considering various supersymmetric particles and experimental constraints, and highlights potential Higgs coupling deviations as future probes.

Contribution

It provides a comprehensive analysis of light neutralino dark matter viability in the MSSM, incorporating latest experimental constraints and identifying Higgs coupling deviations as key signatures.

Findings

Neutralino dark matter can be as light as 15 GeV.

Light charginos near LEP bounds are necessary.

Significant deviations in Higgs couplings are predicted.

Abstract

Light neutralino dark matter can be achieved in the Minimal Supersymmetric Standard Model if staus are rather light, with mass around 100 GeV. We perform a detailed analysis of the relevant supersymmetric parameter space, including also the possibility of light selectons and smuons, and of light higgsino- or wino-like charginos. In addition to the latest limits from direct and indirect detection of dark matter, ATLAS and CMS constraints on electroweak-inos and on sleptons are taken into account using a "simplified models" framework. Measurements of the properties of the Higgs boson at 125 GeV, which constrain amongst others the invisible decay of the Higgs boson into a pair of neutralinos, are also implemented in the analysis. We show that viable neutralino dark matter can be achieved for masses as low as 15 GeV. In this case, light charginos close to the LEP bound are required in addition to light right-chiral staus. Significant deviations are observed in the couplings of the 125 GeV Higgs boson. These constitute a promising way to probe the light neutralino dark matter scenario in the next run of the LHC.