Composite Dirac Neutrinos

Understand

We present a mechanism that naturally produces light Dirac neutrinos.

• The basic idea is that the right-handed neutrinos are composite.
• Any realistic composite model must involve `hidden flavor' chiral symmetries.
• In general some of these symmetries may survive confinement, and in particular, one of them manifests itself at low energy as an exact $B-L$ symmetry.