Absolute neutrino mass as the missing link to the dark sector

TL;DR

This paper discusses how precise measurements of the absolute neutrino mass by KATRIN can connect the Standard Model to dark matter models, revealing new relations and testable predictions in scotogenic theories.

Contribution

It establishes a direct relation between neutrino mass and dark sector parameters, enabling experimental tests of dark matter models through neutrino mass measurements.

Findings

Derived a linear relation between neutrino mass and scalar coupling λ_5.

Identified correlations among dark matter and scalar masses and Yukawa couplings.

Showed that combined KATRIN and lepton flavor violation experiments can probe dark matter parameter space.

Abstract

With the KATRIN experiment, the determination of the absolute neutrino mass scale down to cosmologically favored values has come into reach. We show that this measurement provides the missing link between the Standard Model and the dark sector in scotogenic models, where the suppression of the neutrino masses is economically explained by their only indirect coupling to the Higgs field. We determine the linear relation between the electron neutrino mass and the scalar coupling $\lambda_5$ associated with the dark neutral scalar mass splitting to be $\lambda_5=3.1\times10^{-9}\ m_{\nu_e}/$eV. This relation then induces correlations among the DM and new scalar masses and their Yukawa couplings. Together, KATRIN and future lepton flavor violation experiments can then probe the fermion DM parameter space, irrespective of the neutrino mass hierarchy and CP phase.