Neutralino Dark Matter with Inert Higgsinos and Singlinos

TL;DR

This paper explores a supersymmetric model with inert Higgsinos and singlinos, showing it can naturally produce a light neutralino as dark matter candidate consistent with relic abundance.

Contribution

It introduces a model with inert Higgsinos and singlinos that yields a decoupled neutralino sector capable of explaining dark matter independently.

Findings

Light neutralino can account for dark matter relic abundance.

Inert Higgsinos and singlinos form an almost decoupled neutralino sector.

Model predicts specific conditions on tan beta for dark matter compatibility.

Abstract

We discuss neutralino dark matter arising from supersymmetric models with extra inert Higgsinos and singlinos, where inert means that their scalar partners do not get vacuum expectation values. As an example, we consider the extended neutralino sector of the E$_6$SSM, which predicts three families of Higgs doublet pairs, plus three singlets, plus a $Z'$, together with their fermionic superpartners. We show that the two families of inert doublet Higgsinos and singlinos predicted by this model provide an almost decoupled neutralino sector with a naturally light LSP which can account for the cold dark matter relic abundance independently of the rest of the model, providing that the ratio of the two usual Higgs doublets satisfies tan beta < 2.