Pion-nucleon phase-shift analyses: 0-350 MeV

Abstract

Energy-dependent and energy-independent partial-wave analyses of the low-energy ${\pi }^{\pm }p$ elastic and charge-exchange scattering data are presented. Unique, unitary, energy-dependent solutions giving a $\frac{{\chi }^2}{\mathrm{datum}}$ of 1 are obtained. The solutions exhibit charge splitting in both the $S_{31}$ and $P_{33}$ partial waves. The $T$-matrix pole positions and residues of the ${\Delta }^{++}$ and ${\Delta }^0$ resonances are determined to a new precision. $D$ and $F$ waves are well determined independent of theoretical constraints. New values for the $S$- and $P$-wave scattering lengths and effective ranges are reported.