Sub-TeV Singlet Scalar Dark Matter and Electroweak Vacuum Stability with Vector Like Fermions

TL;DR

This paper explores a sub-TeV scalar singlet dark matter model extended with vector-like fermions, which enables relic density, direct detection compliance, and electroweak vacuum stability up to the Planck scale, with potential neutrino mass generation.

Contribution

It introduces a minimal extension with vector-like fermions that achieves dark matter viability and electroweak vacuum stability simultaneously, including neutrino mass generation.

Findings

Scalar singlet DM with a few hundred GeV mass satisfies all constraints.

Vector-like fermions stabilize the electroweak vacuum up to the Planck scale.

Model with three generations of leptons can generate light neutrino masses.

Abstract

We study a scalar singlet dark matter (DM) having mass in sub-TeV regime by extending the minimal scalar singlet DM setup by additional vector like fermions. While the minimal scalar singlet DM satisfies the relic and direct detection constraints for mass beyond TeV only, presence of its portal coupling with vector like fermions opens up additional co-annihilation channels. These vector like fermions also help in achieving electroweak vacuum stability all the way up to Planck scale. We find that for one generation of vector like quarks consisting of a $SU(2)_L$ doublet and a singlet, scalar singlet DM with mass a few hundred GeV can indeed satisfy relic, direct detection and other relevant constraints while also making the electroweak vacuum absolutely stable. The same can be achieved by introducing vector like leptons too, but with three generations. While the model with vector like quarks is minimal, the three generations of vector like lepton doublet and neutral singlet can also give rise to light neutrino mass at one loop level.