Mixed Neutralino Dark Matter in Nonuniversal Gaugino Mass Models

TL;DR

This paper explores nonuniversal gaugino mass models in supergravity, showing that mixed neutralino states can produce viable dark matter relic densities and promising signals for detection in astrophysical and collider experiments.

Contribution

It introduces specific nonuniversal gaugino mass models from mixed superfield contributions, analyzing their dark matter properties and detection prospects.

Findings

Mixed bino-higgsino and bino-wino-higgsino states yield compatible relic densities.

Models predict detectable signals in direct and indirect dark matter searches.

Promising collider signatures are expected at the LHC.

Abstract

We have considered nonuniversal gaugino mass models of supergravity, arising from a mixture of two superfield contributions to the gauge kinetic term, belonging to a singlet and a nonsinglet representation of the GUT group. In particular we analyse two models, where the contributing superfields belong to the singlet and the 75-dimensional, and the singlet and the 200-dimensional representations of SU(5). The resulting lightest superparticle is a mixed bino-higgsino state in the first case and a mixed bino-wino-higgsino state in the second. In both cases one obtains cosmologically compatible dark matter relic density over broad regions of the parameter space. We predict promising signals in direct dark matter detection experiments as well as in indirect detection experiments via high energy neutrinos coming from their pair-annihilation in the Sun. Besides, we find interesting $\gamma$-ray signal rates that will be probed in the Fermi Gamma-ray Space Telescope. We also expect promising collider signals at LHC in both cases.