2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/51014A 6-component "wave function" (not field, but S-matrix interpretable) for a massive spin-1 particle parallels the Dirac "chirality-doubled" 4-component wave function for a spin-1/2 particle, by pairing two wave functions for same spin but opposite "handedness". The correlated "opposite-parity" pair of complex 3-vectors defines a fluctuating spin-correlated lightlike ``internal velocity" as well as an independent "external rapidity". Extension from fermions to vector bosons of the velocity-fluctuation ("zitterbewegung") interpretation of rest mass weakens theoretical motivation for elementary scalar bosons.This paper shows how a generalization of Dirac's method of generating a finite velocity, hence nonzero mass, of a spin 1/2 particle built out of massless components works also for spin-1 particles, without any need to introduce spin-zero companionsHigh Energy Physics - Theorytext