2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/185125A complete set of formulae in terms of the moment-operator expansion is presented for the two-meson, two-photon and fermion-antifermion states that can be used in the analysis of scalar (S) and pseudoscalar (P) meson production in anti-p p and gamma-gamma collisions: anti-p p -> SS, PP, SP and gamma gamma -> SS, PP, SP.21 pages, Latex, no fuguresHigh Energy Physics - Phenomenologytext