Probing GeV-scale MSSM neutralino dark matter in collider and direct detection experiments

TL;DR

This paper investigates the viability of GeV-scale neutralino dark matter within the MSSM framework, analyzing collider and direct detection constraints to identify allowed parameter space and future detection prospects.

Contribution

It provides a comprehensive analysis of light neutralino dark matter in the MSSM, considering recent experimental constraints and exploring future detection possibilities.

Findings

Neutralino DM above 6 GeV is excluded by XENON-1T limits.

Parameter space below 6 GeV can be tested by future germanium detectors.

Light neutralino DM can still satisfy relic density via $h$ resonance or pair annihilation.

Abstract

Given the recent constraints from the dark matter (DM) direct detections, we examine a light GeV-scale (2-30 GeV) neutralino DM in the alignment limit of the Minimal Supersymmetric Standard Model (MSSM). In this limit without decoupling, the heavy CP-even scalar $H$ plays the role of the Standard Model (SM) Higgs boson while the other scalar $h$ can be rather light so that the DM can annihilate through the $h$ resonance or into a pair of $h$ to achieve the observed relic density. With the current collider and cosmological constraints, we find that such a light neutralino DM above 6 GeV can be excluded by the XENON-1T (2017) limits while the survivied parameter space below 6 GeV can be fully covered by the future germanium-based light dark matter detections (such as CDEX), by the Higgs coupling precison measurements or by the production process $e^+e^- \to hA$ at an electron-positron collider (Higgs factory).