Inverse amplitude method in ππ scattering in chiral perturbation theory to two loops

The inverse amplitude method is used to unitarize the two-loop {π}{π} 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 l1,2,3,4 and existing experimental data is undertaken. A comparison to standard resonance saturation values for the two-loop coefficients b1,2,3,4,5,6 is also carried out. Crossing violations are quantified and the convergence of the expansion is discussed.