Supersymmetric Higgs-portal and X-ray lines

TL;DR

This paper explores a supersymmetric Higgs-portal model with a Dirac singlet fermion as dark matter, explaining X-ray lines and predicting observable collider signatures.

Contribution

It introduces a novel supersymmetric Higgs-portal framework with a Dirac singlet fermion, detailing its relic density and collider phenomenology.

Findings

Correct relic density via co-annihilation with Higgsinos

Potential displaced vertices at the LHC

Explanation of X-ray line through dark matter decay

Abstract

We consider a Dirac singlet fermion as thermal dark matter for explaining the X-ray line in the context of a supersymmetric Higgs-portal model or a generalized Dirac NMSSM. The Dirac singlet fermion gets a mass splitting due to their Yukawa couplings to two Higgs doublets and their superpartners, Higgsinos, after electroweak symmetry breaking. We show that a correct relic density can be obtained from thermal freeze-out, due to the co-annihilation with Higgsinos for the same Yukawa couplings. We discuss the phenomenology of the Higgsinos in this model such as displaced vertices at the LHC.