We derive new constraints on light vectors coupled to Standard Model (SM)
fermions, when the corresponding SM current is broken by the chiral anomaly.
Cancellation of the anomaly by heavy fermions results, in the low-energy
theory, in Wess-Zumino type interactions between the new vector and the SM
gauge bosons. These interactions are determined by the requirement that the
heavy sector preserves the SM gauge groups, and lead to (energy / vector
mass)^2 enhanced rates for processes involving the longitudinal mode of the new
vector. Read More