Light neutrino mass spectrum with one or two right-handed singlet fermions added

TL;DR

This paper investigates minimal extensions of the Standard Model with one or two right-handed neutrinos, including a second Higgs doublet, and analyzes their ability to produce neutrino masses consistent with experimental data through one-loop corrections.

Contribution

It introduces a model with one or two right-handed singlet fermions and a second Higgs doublet, providing a detailed numerical analysis of neutrino masses and mixing angles.

Findings

Neutrino masses compatible with experimental data are achievable.

Parameter scans identify regions fitting solar and atmospheric neutrino oscillations.

One-loop corrections significantly impact neutrino mass predictions.

Abstract

We analyse two cases of the minimal extension of the Standard Model when one or two right-handed fields are added to the three left-handed fields. A second Higgs doublet (two Higgs doublet model - 2HDM) is included in our model. We calculate one-loop radiative corrections to the mass parameters which produce mass terms for the neutral leptons. In both cases we numerically analyse light neutrino masses as functions of the heavy neutrino masses. Parameters of the model are varied to find light neutrino masses that are compatible with experimental data of solar and atmospheric neutrino mass differences for normal hierarchy. We choose values for the parameters of the tree-level by numerical scans, where we look for the best agreement between computed and experimental neutrino oscillation angles.