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

Understand

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.