2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/93212The Bargmann-Wigner (BW) scalar product is a particular case of a larger class of scalar products parametrized by a family of world-vectors. The choice of null and $p$-dependent world-vectors leads to BW amplitudes which behave as local $SU(2)$ spinors (BW-spinors) if {\it passive\/} transformations are concerned. The choice of null directions leads to a simplified formalism which allows for an application of ordinary, manifestly covariant spinor techniques in the context of infinite dimensional unitary representations of the Poincaré group.revtex, 14 pagesQuantum PhysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext