Dark Matter in a Constrained $E_6$ Inspired SUSY Model

TL;DR

This paper explores a constrained $E_6$ inspired supersymmetric model with custodial symmetry, identifying viable dark matter candidates, analyzing experimental constraints, and highlighting prospects for detection at LHC and XENON1T.

Contribution

It introduces a novel $E_6$ inspired SUSY model with custodial symmetry, analyzing dark matter candidates and experimental constraints in this specific framework.

Findings

Higgsino and bino-Higgsino neutralinos can account for dark matter relic density.

LUX 2016 limits strongly constrain bino-Higgsino scenarios.

Large parameter space with Higgsino dark matter is discoverable by XENON1T.

Abstract

We investigate dark matter in a constrained $E_6$ inspired supersymmetric model with an exact custodial symmetry and compare with the CMSSM. The breakdown of $E_6$ leads to an additional $U(1)_N$ symmetry and a discrete matter parity. The custodial and matter symmetries imply there are two stable dark matter candidates, though one may be extremely light and contribute negligibly to the relic density. We demonstrate that a predominantly Higgsino, or mixed bino-Higgsino, neutralino can account for all of the relic abundance of dark matter, while fitting a 125 GeV SM-like Higgs and evading LHC limits on new states. However we show that the recent LUX 2016 limit on direct detection places severe constraints on the mixed bino-Higgsino scenarios that explain all of the dark matter. Nonetheless we still reveal interesting scenarios where the gluino, neutralino and chargino are light and discoverable at the LHC, but the full relic abundance is not accounted for. At the same time we also show that there is a huge volume of parameter space, with a predominantly Higgsino dark matter candidate that explains all the relic abundance, that will be discoverable with XENON1T. Finally we demonstrate that for the $E_6$ inspired model the exotic leptoquarks could still be light and within range of future LHC searches.