Application of the Accelerated-Convergence Expansion to Pion-Nucleon Scattering

Abstract

The accelerated-convergence expansion has generated some controversy in applications to single-energy analyses of kaon-nucleon scattering. We have applied this expansion to pion-nucleon scattering at 490 MeV as the first test of the method in a region where strong $s$-channel effects are in evidence. The ${\ensuremath{\chi}}^{2}$ values obtained from the accelerated-convergence-expansion analyses are in no case lower than those obtained from the corresponding conventional analyses, and we make several comments to explain this result.