Optimal techniques for the extrapolation of SU2 violating πnucleon amplitudes

The letter presents some results obtained applying optimal techniques for analytic extrapolation to the latest phase-shift analysis. The followed method gives absolute upper bounds on the extrapolation errors and it does not require any strong smoothness assumption in the energy variable. The approach follows closely the method first outlined by Ciulli and Fischer which use ''truncated Carleman'' functions to weight the functions to be extrapolated to points internal to their holomorphy domain