Hierarchy of Interactions in Unified Gauge Theories

We are really measuring the sum of the cross sections vpver+Em and ppvpm. ln, l ~ 0, but since our neutrino spectrum peaks at 500 MeV/c and is down by an order of magnitude by 1500 MeV/c, we expect the contribution of the final states with additional m. 's to be very small. J. Campbell et al. , Phys. Bev. Lett. 30, 385 (1973). More details of the experiment are given by S. J. Barish, Argonne National Laboratory Report No. ANL/ HEP 7418 (unpublished). Y. Cho et a/. , in Proceedings of the Sixteenth International Conference on High Energy Physics, The University of Chicago and National Accelerator Laboratory, 1972 (unpublished), paper 473. In doing this we are implicitly assuming that the characteristics of our neutraland charged-current events are the same. This is true on the Salam-Weinberg model but may not be true in general. For the charged-current events, we measure the ratio N(vp p ps+@ )/N(vp V, pm+)= 0. I+ 0.05and, therefore, we reduce the observed vs/V, pm+ ratios by 109o. In addition, for the one-prong+y events, a small contribution from the reaction vd vnmo(p ) has been subtracted. S. Adler, private communication. 9J. Sakurai, Phys. Bev. D 9, 250 (1974).