Symmetry, dark matter and LHC phenomenology of the minimal $\nu$SM

TL;DR

This paper explores a minimal neutrino model where a keV-scale sterile neutrino serves as warm dark matter, with implications for symmetry, neutrino mixing, and potential LHC signatures.

Contribution

It introduces a minimal $ u$SM model with an approximate Friedberg-Lee symmetry explaining light right-handed neutrinos and predicts testable collider effects.

Findings

KeV neutrino can be a warm dark matter candidate.

Model predicts large neutrino mixing effects at the LHC.

Strong correlation between light and heavy neutrino mixing parameters.

Abstract

A sterile neutrino with a mass of a few keV can play the role of a warm dark matter(DM). This can be realized in seesaw models with 3 left- and 3 right-handed neutrinos. It is possible to identify the keV neutrino to be one of the right-handed neutrinos leaving the other two to be much more heavier, the $\nu$SM model. We show that with this realization of keV neutrino DM, the model has an approximate Friedberg-Lee symmetry providing a natural explanation for the lightness of the right-handed neutrino. We also find that in this model the mixing parameters couple light and heavy neutrinos are strongly correlated, and can be large enough to have testable effects at the LHC for the two heavy right-handed neutrinos to be in the hundred-GeV range.