Higgsino Dark Matter and the Cosmological Gravitino Problem

TL;DR

This paper explores Higgsino dark matter as a solution to the cosmological gravitino problem, emphasizing non-thermal production mechanisms and experimental constraints in supersymmetric models.

Contribution

It demonstrates that Higgsinos can be viable sub-TeV dark matter candidates through non-thermal production in models addressing the gravitino problem, considering both anomaly and modulus mediation.

Findings

Higgsinos can account for dark matter via non-thermal production.

Constraints from direct and indirect detection limit Higgsino parameter space.

Heavy moduli and gravitinos are necessary to avoid cosmological issues.

Abstract

We motivate Higgsino dark matter from a solution to the cosmological moduli/gravitino problem. Cosmological moduli/gravitino should be heavy enough to decay before the onset of Big Bang Nucleosynthesis, and this requirement typically forces gauginos to have masses above a TeV in Type IIB compactifications. Higgsinos emerge as the viable sub-TeV dark matter candidates if anomaly and modulus mediated contributions to supersymmetry breaking are both competitive. Obtaining the correct relic density in this mass range forces Higgsinos to be produced non-thermally from the decay of a modulus. We outline constraints arising from indirect and direct detection experiments in this context, as well as theoretical constraints such as the overproduction of dark matter from gravitino decay.