Question of Parity Conservation in Weak Interactions

the r+(=E s+) mesons. On the other hand, analyses' of the decay products of r+ strongly suggest on the grounds of angular momentum and parity conservation that the ~+ and 8 are not the same particle. This poses a rather puzzling situation that has been extensively discussed. ' One way out of the difhculty is to assume that parity is not strictly conserved, so that 0+ and v-+ are two diGerent decay modes of the same particle, which necessarily has a single mass value and a single lifetime. We wish to analyze this possibility in the present paper against the background of the existing experimental evidence of parity conservation. It will become clear that existing experiments do indicate parity conservation in strong and electromagnetic interactions to a high degree of accuracy, but that for the weak interactions (i.e., decay interactions for the mesons and hyperons, and various Fermi interactions) parity conservation is so far only an extrapolated hypothesis unsupported by experimental evidence. (One might even say that the present 8—v puzzle may be taken as an indication that parity conservation is violated in weak interactions. This argument is, however, not to be taken seriously because of the paucity of our present knowledge concerning the nature of the strange particles. It supplies rather an incentive for an examination of the question of parity conservation. ) To decide unequivocally whether parity is conserved in weak interactions, one must perform an experiment to determine whether weak interactions differentiate the right from the left. Some such possible experiments will be