Parametrizing the Neutrino sector of the seesaw extension in tau decays

TL;DR

This paper explores a minimal extension of the Standard Model with right-handed neutrinos and a second Higgs doublet, analyzing how radiative corrections can produce neutrino masses consistent with experimental oscillation data.

Contribution

It parametrizes the neutrino sector within a seesaw extension including a second Higgs doublet and computes one-loop corrections to neutrino masses.

Findings

Neutrino masses can be generated consistent with experimental data.

Parameter space analysis supports normal and inverted hierarchies.

Radiative corrections significantly affect neutrino mass predictions.

Abstract

The Standard Model includes neutrinos as massless particles, but neutrino oscillations showed that neutrinos are not massless. A simple extension of adding gauge singlet fermions to the particle spectrum allows normal Yukawa mass terms for neutrinos. The smallness of the neutrino masses can be well understood within the seesaw mechanism. 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 is included in our model. We calculate the 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 neutrinos masses. Parameters of the model are varied to find light neutrino masses that are compatible with experimental data of solar and atmospheric neutrino oscillations for normal and inverted hierarchy.