Flavor changing neutral couplings for leptons

TL;DR

This paper reviews the conditions for lepton-flavor conservation, discusses neutrino oscillations due to mass eigenstates, and explores how small neutrino masses suppress their couplings to neutral scalars across various models.

Contribution

It provides a comparative analysis of lepton-flavor conservation conditions and introduces the impact of small neutrino masses on their interactions in different theoretical frameworks.

Findings

Neutrino masses are very small, suppressing their couplings to neutral scalar fields.

Lepton-flavor conservation conditions are similar in leptonic and quark sectors.

Neutrino oscillations arise from unitary superpositions of mass eigenstates.

Abstract

The article reviews the conditions for lepton-flavor conservation in leptonic interactions. The conditions are similar to those developed in the quark sector. For neutrinos the mass eigenstates are unitary superpositions of flavor states which together with small mass differences produce neutrino oscillations. A new property for neutrinos is the fact that their masses are very small suppressing their couplings to neutral scalar fields. The results are demonstrated in several models.