CERN and NAL groups claim evidence for neutral currents Available to Purchase

Two experiments, one at CERN and the other at the National Accelerator Laboratory, are showing evidence for the existence of neutral currents. They are finding events in which a neutrino interacts with a nucleon and, instead of producing a muon or an electron, yields hadrons without a charged lepton. Because of the recent interest in theories that attempt to unify the weak and electromagnetic interactions, such as those proposed by Steven Weinberg (PHYSICS TODAY, April 1972, page 17) and by Abdus Salam, the new observations are exciting great interest. These theories generally require the existence of neutral currents.