Split-SUSY dark matter in light of direct detection limits

TL;DR

This paper analyzes how current and future XENON direct detection limits constrain neutralino dark matter in split supersymmetry, showing significant exclusions and implications for neutralino properties if dark matter remains undetected.

Contribution

It provides a comprehensive scan of split-SUSY parameter space under experimental constraints and predicts the impact of future direct detection experiments on neutralino dark matter.

Findings

Current XENON100 limits exclude large parts of parameter space.

Future experiments could cover even more parameter space.

If dark matter remains undetected, the neutralino is likely bino-like with Higgs-mediated annihilation.

Abstract

We examine the present and future XENON limits on the neutralino dark matter in split supersymmetry (split-SUSY). Through a scan over the parameter space under the current constraints from collider experiments and the WMAP measurement of the dark matter relic density, we find that in the allowed parameter space a large part has been excluded by the present XENON100 limits and a further largish part can be covered by the future exposure (6000 kg-day). In case of unobservation of dark matter with such an exposure in the future, the lightest neutralino will remain bino-like and its annihilation is mainly through exchanging the SM-like Higgs boson in order to get the required relic density.