Dirac or Inverse Seesaw Neutrino Masses from Gauged B - L Symmetry

TL;DR

This paper explores alternative anomaly-free solutions for gauged B - L symmetry that lead to Dirac or inverse seesaw neutrino masses, contrasting with the conventional Majorana seesaw mechanism, and applies these to neutrino mixing with S3 symmetry.

Contribution

It introduces new anomaly-free B - L models that produce Dirac or inverse seesaw neutrino masses, expanding beyond the traditional Majorana framework.

Findings

Alternative B - L solutions yield Dirac/inverse seesaw neutrino masses.

Application of S3 flavor symmetry to neutrino mixing.

Comparison with conventional Majorana seesaw models.

Abstract

The gauged $B - L$ symmetry is one of the simplest and well studied extension of standard model. In the conventional case, addition of three singlet right handed neutrinos each transforming as $-1$ under the $B - L$ symmetry renders it anomaly free. It is usually assumed that the $B - L$ symmetry is spontaneously broken by a singlet scalar having two units of $B - L$ charge, resulting in a natural implementation of Majorana seesaw mechanism for neutrinos. However, as we discuss in this proceeding, there is another simple anomaly free solution which leads to Dirac or inverse seesaw masses for neutrinos. These new possibilities are explored along with an application to neutrino mixing with $S_3$ flavour symmetry.