2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/83590A comment on a recent paper by P. Froelich et. al., Phys. Rev. Lett., 84, 4577 (2000) on hydrogen-antihydrogen collisions and on matter-antimatter reactions in general. The center of mass of a stable HHbar system has prochiral character. It is not necessary to look for large scale anti-matter domains at distances Mpc away or at the cosmological horizon.1 pag, submittedGeneral PhysicsChemical Physicstext