2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/178921The inverse amplitude method is used to unitarize the two loop $ππ$ scattering amplitudes of SU(2) Chiral Perturbation Theory in the $I=0,J=0$, $I=1,J=1$ and $I=2,J=0$ channels. An error analysis in terms of the low energy one-loop parameters $\bar l_{1,2,3,4,}$ and existing experimental data is undertaken. A comparison to standard resonance saturation values for the two loop coefficients $\bar b_{1,2,3,4,5,6} $ is also carried out. Crossing violations are quantified and the convergence of the expansion is discussed.(Latex, epsfig) 30 pages, 13 figures, 8 tablesHigh Energy Physics - Phenomenologytext