Chiral Dark Sectors, Neutrino Masses, and Dark Matter

The Physics behind nonzero neutrino masses and the nature of the so-called dark matter remain elusive. Both, however, point to new degrees of freedom that couple very weakly to the known Standard Model degrees of freedom. I explore the possibility that these new degrees of freedom are the matter particles of a new chiral gauge symmetry under which the Standard Model degrees of freedom are gauge singlets. In more detail, I discuss on mechanism for constructing chiral gauge theories and present two concrete models: one based on a U(1) chiral gauge theory, the other on an SU(3)xSU(2) chiral gauge theory.