2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/199571The unitarity relation, Im(A)=T* A, is derived for a three-body production amplitude, A, that consists of a complex linear combination of elements of the two-body scattering amplitude, T. We conclude that the unitarity relation does not impose a realness condition on the coefficients in the expansion of, A, in terms of, T.4 pages plain LaTeXHigh Energy Physics - Phenomenologytext