2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/40225The pionium lifetime is calculated in the framework of the quasipotential-constraint theory approach, including the sizable electromagnetic corrections. The framework of generalized chiral perturbation theory allows then an analysis of the lifetime value as a function of the pion S-wave scattering lengths with isospins I=0,2, the latter being dependent on the quark condensate value.3 pages, 1 figure, latex, uses sprocl.sty. Talk given at the International Conference Quark Confinement and the Hadron Spectrum, Vienna, 3-8 July 2000. To appear in the ProceedingsHigh Energy Physics - Phenomenologytext