2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/93264Various theories of spinning particles are interpreted as realizing elements of an underlying geometric theory. Classical particles are described by trajectories on the Poincare group. Upon quantization an eleven-dimensional Kaluza-Klein type theory is obtained which incorporates spin and isospin in a local SL(2,C) x U(1) x SU(2) theory with broken U(1)x SU(2) part.9 pages LatexQuantum PhysicsGeneral Relativity and Quantum Cosmologytext