« Handed » particle of spin 1/2 with finite mass

Abstract

It is possible to formulate a four-component spinor theory for a particle of spin 1/2 with a definite chirality (handed-ness), which has a finite mass. Interaction between an achiral (nonhanded) spinor and a chiral spinor requires an eight-component frame-work. Such an interaction manifests a parity-violating property. Two formulations are possible: 1) The theory can be made invariant separately for time-reversal and for the combination of space-inversion and charge-conjugation, or 2) it can be made invariant for space-and-time-inversion and for charge-conjugation. The present theory may have applications for hyperons. The Salam-Lee-Yang-Landau type (1) of neutrino theory can be derived from the present formalism for the case m = 0. (See Appendix). © 1957 Società Italiana di Fisica.