2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/181839To describe the weak three-body B decays into pi+ pi- K, we recently derived amplitudes based on two-body QCD factorization followed by pi+ pi- final state interactions in isoscalar S- and isovector P-waves. We study here the sensitivity of the results to the values of the B to f0(980) transition form factor and to the effective decay constant of the f0(980).Contribution to the Few Body 18 conference in Santos, Brazil, August 21-26, 2006, 5 pages, to be published in Nuclear Physics AHigh Energy Physics - Phenomenologytext