Light Higgsino Dark Matter from Non-thermal Cosmology

TL;DR

This paper investigates how non-standard cosmological history affects higgsino dark matter abundance, showing that light higgsinos are viable with low reheating temperatures and discussing implications for detection and string theory models.

Contribution

It provides a model-independent analysis of non-thermal higgsino dark matter production and explores the implications for detection experiments and string theory motivated cosmologies.

Findings

Light higgsino dark matter is possible with reheating temperatures near 1 GeV.

Fermi-LAT data rules out higgsinos below 300 GeV in non-thermal scenarios.

Future indirect detection and collider experiments can probe the full parameter space.

Abstract

We study the scenario of higgsino dark matter in the context of a non-standard cosmology with a period of matter-domination prior to Big-Bang nucleosynthesis. Matter-domination changes the dark matter relic abundance if it ends via reheating to a temperature below the higgsino thermal freeze-out temperature. We perform a model independent analysis of the higgsino dark matter production in such scenario. We show that light higgsino-type dark matter is possible for reheating temperatures close to 1 GeV. We study the impact of dark matter indirect detection and collider physics in this context. We show that Fermi-LAT data rules out non-thermal higgsinos with masses below 300 GeV. Future indirect dark matter searches from Fermi-LAT and CTA would be able to cover essentially the full parameter space. Contrary to the thermal case, collider signals from a 100 TeV collider could fully test the non-thermal higgsino. In the second part of the paper we discuss the motivation of such non-thermal cosmology from the perspective of string theory with late-time decaying moduli for both KKLT and LVS moduli stabilization mechanisms. We describe the impact of embedding dark matter higgsino in these scenarios.