Phenomenology of left-right symmetric dark matter

TL;DR

This paper explores dark matter candidates within low-scale left-right symmetric models, analyzing their stability, relic abundance, and detection prospects, including collider signals and gamma-ray observations, with a focus on various fermionic and scalar multiplets.

Contribution

It provides a comprehensive phenomenological analysis of fermionic and scalar dark matter candidates in left-right symmetric models, highlighting their stability, relic density, and experimental signatures.

Findings

Majorana candidates are highly testable at colliders.

Scalar candidates exhibit rich phenomenology due to additional interactions.

Large gamma-ray flux predictions make these candidates promising for astrophysical searches.

Abstract

We present a detailed study of dark matter phenomenology in low-scale left-right symmetric models. Stability of new fermion or scalar multiplets is ensured by an accidental matter parity that survives the spontaneous symmetry breaking of the gauge group by scalar triplets. The relic abundance of these particles is set by gauge interactions and gives rise to dark matter candidates with masses above the electroweak scale. Dark matter annihilations are thus modified by the Sommerfeld effect, not only in the early Universe, but also today, for instance, in the Center of the Galaxy. Majorana candidates - triplet, quintuplet, bi-doublet, and bi-triplet - bring only one new parameter to the model, their mass, and are hence highly testable at colliders and through astrophysical observations. Scalar candidates - doublet and 7-plet, the latter being only stable at the renormalizable level - have additional scalar-scalar interactions that give rise to rich phenomenology. The particles under discussion share many features with the well-known candidates wino, Higgsino, inert doublet scalar, sneutrino, and Minimal Dark Matter. In particular, they all predict a large gamma-ray flux from dark matter annihilations, which can be searched for with Cherenkov telescopes. We furthermore discuss models with unequal left-right gauge couplings, $g_R \neq g_L$, taking the recent experimental hints for a charged gauge boson with 2 TeV mass as a benchmark point. In this case, the dark matter mass is determined by the observed relic density.