Singlet fermionic dark matter with Veltman conditions

TL;DR

This paper investigates a minimal fermionic dark matter model with a singlet scalar, addressing the scalar mass hierarchy problem via Veltman conditions, and explores its phenomenological implications including relic abundance and direct detection prospects.

Contribution

It introduces a renormalizable fermionic dark matter model satisfying Veltman conditions, constraining parameters with experimental data and analyzing its detection prospects.

Findings

Allowed parameter space consistent with relic abundance

Predicted elastic scattering cross section for direct detection

Constraints from Veltman condition and unitarity

Abstract

We reexamine a renormalizable model of a fermionic dark matter with a gauge singlet Dirac fermion and a real singlet scalar which can ameliorate the scalar mass hierarchy problem of the Standard Model (SM). Our model setup is the minimal extension of the SM for which a realistic dark matter (DM) candidate is provided and the cancellation of one-loop quadratic divergence to the scalar masses can be achieved by the Veltman condition (VC) simultaneously. This model extension, although renormalizable, can be considered as an effective low-energy theory valid up to cut-off energies about 10 TeV. We calculate the one-loop quadratic divergence contributions of the new scalar and fermionic DM singlets, and constrain the model parameters using the VC and the perturbative unitarity conditions. Taking into account the invisible Higgs decay measurement, we show the allowed region of new physics parameters satisfying the recent measurement of relic abundance. With the obtained parameter set, we predict the elastic scattering cross section of the new singlet fermion into target nuclei for a direct detection of the dark matter. We also perform the full analysis with arbitrary set of parameters without the VC as a comparison, and discuss the implication of the constraints by the VC in detail.