Sterile neutrino dark matter in warped extra dimensions

TL;DR

This paper explores a five-dimensional warped extra dimension model where sterile neutrinos serve as dark matter, produced mainly from radion decay, with warp factors reducing fine-tuning issues common in four-dimensional models.

Contribution

It introduces a novel 5D warped extra dimension framework for sterile neutrino dark matter, addressing fine-tuning problems through warp factor suppressions and radion decay mechanisms.

Findings

Sterile neutrino production via radion decay around the electroweak scale.

Warp factors reduce parameter fine-tuning in the model.

The model offers a viable dark matter candidate with suppressed fine-tuning.

Abstract

We consider a (long-lived) sterile neutrino dark matter scenario in a five dimensional (5D) warped extra dimension model where the fields can live in the bulk, which is partly motivated from the absence of the absolutely stable particles in a simple Randall-Sundrum model. The dominant production of the sterile neutrino can come from the decay of the radion (the scalar field representing the brane separation) around the electroweak scale. The suppressions of the 4D parameters due to the warp factor and the small wave function overlaps in the extra dimension help alleviate the exceeding fine-tunings typical for a sterile neutrino dark matter scenario in a 4D setup.