sin${}^2{\theta }_W$ theory and new physics

Abstract

After briefly discussing the importance of the precise measurement of the weak mixing angle, we discuss the implication of the dark Z on the low-Q^2 parity tests. The dark Z is a very light (roughly, MeV - GeV scale) gauge boson, which couples to the electromagnetic current as well as the weak neutral current.

Comments: More descriptions and references. For PhiPsi 15 proceedings