2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/177695We present a new method for the determination of the pion-pion scattering lenght combination a0-a2, based on the study of the pi0-pi0 spectrum in K->pi+ pi0 pi0 in the vicinity of the pi+ pi- threshold. The method requires a minimum of theoretical input, and is potentially very accurate.8 pages, 2 figures -- corrected two typosHigh Energy Physics - Phenomenologytext