Low Scale Left-Right Symmetry and Warm Dark Matter

TL;DR

This paper explores a minimal left-right symmetric model where keV-scale right-handed neutrinos serve as warm dark matter, with relic abundance managed through late decays and a narrow gauge boson mass window accessible at the LHC.

Contribution

It demonstrates the viability of keV right-handed neutrinos as warm dark matter within a minimal left-right symmetric framework, including relic abundance mechanisms and collider testability.

Findings

Right-handed neutrinos can be warm dark matter candidates.

Relic abundance is achieved via late decays of heavier neutrinos.

Gauge boson mass window is within LHC reach.

Abstract

We study the scenario of dark matter in the minimal left-right symmetric theory at the TeV scale. The only viable candidate is found to be the lightest right-handed neutrino with a mass of keV. To satisfy the dark matter relic abundance, the relic yield is diluted by late decays of the two heavier neutrinos. We point out that the QCD phase transition temperature coincidences with the typical freeze-out temperature governed by right-handed interactions, which helps to alleviate the problem of overproduction. A careful numerical study reveals a narrow window for the mass of the right-handed gauge boson, within the reach of the LHC.