Spontaneous symmetry breaking in this interaction rotates a vector boson to a photonic field in a phenomenon parameterized by this interaction’s namesake mixing angle. The quanta of this interaction were first observed by the UA1 (15[1])and UA2 experiments at CERN. Gamma ray and electron emission data were analyzed by Chien-Shiung (*) Wu’s team to prove (10[1])that this interaction does not conserve parity. The CKM matrix describes (-5[1])flavor oscillations of quarks mediated by this interaction. The W and Z bosons mediate this interaction (10[1])which Glashow, Weinberg, and Salam unified with electromagnetism. Beta decay is explained by, for 10 points, what fundamental force, which, despite its name, is not the least powerful? ■END■ (10[1])