Minimal dark matter in type III seesaw

TL;DR

This paper proposes a new dark matter candidate within the supersymmetric type III seesaw model, highlighting its potential detectability through astrophysical signals and unique collider signatures, especially involving a nearly degenerate charged scalar.

Contribution

It introduces a novel dark matter candidate in the supersymmetric type III seesaw framework with distinctive collider and astrophysical signatures.

Findings

Dark matter candidate can have the correct relic abundance with non-standard cosmology.

Enhanced annihilation cross-section leads to detectable astrophysical signals.

Unique collider signatures include slowly-moving, highly-ionizing tracks and displaced vertices.

Abstract

We explore the possibility of a new dark matter candidate in the supersymmetric type III seesaw mechanism where a neutral scalar component of the Y=0 triplet can be the lightest supersymmetric particle. Its thermal abundance can be in the right range if non-standard cosmology such as kination domination is assumed. The enhanced cross-section of the dark matter annihilation to W+W- can leave detectable astrophysical and cosmological signals whose current observational data puts a lower bound on the dark matter mass. The model predicts the existence of a charged scalar almost degenerate with the dark matter scalar and its lifetime lies between 5.5 cm and 6.3 m. It provides a novel opportunity of the dark mater mass measurement by identifying slowly-moving and highly-ionizing tracks in the LHC experiments. If the ordinary lightest supersymmetric particle is the usual Bino, its decay leads to clean signatures of same-sign di-lepton and di-charged-scalar associated with observable displaced vertices which are essentially background-free and can be fully reconstructed.