Experimental results on one-pion neutral current reaction in all channels induced by antineutrinos at CERN PS

Abstract Single pion production, in antineutrino-nucleon interactions via the neutral current, has been studied in the bubble chamber Gargamelle, filled with propane. Complete analysis of the secondaries, including π 0, s, has allowed a detailed study of all channels. After background and nuclear corrections, results are obtained which can be interpreted in terms of isospin structure of the neutral weak current and of the Salam-Weinberg angle. Agreement is found with the currently accepted value of sin 2 θ W and the data suggest an important contribution of I = 3 2 final states.