Pi pi scattering in three flavor ChPT : ππ scattering in three flavour ChPT
We present the scattering lengths for the pi-pi processes in the three flavour Chiral Perturbation Theory (ChPT) framework at next-to-next-to-leading order. We then combine this calculation with the determination of the parameters from $Ke4 and the masses and decay constants and compare with the results of a dispersive analysis of pi-pi scattering. The comparison indicates a small but nonzero valu