Analyzing powers forπpelastic scattering between 57 and 139 MeV

Abstract

Analyzing powers for $\ensuremath{\pi}p$ elastic scattering at bombarding energies below the $\ensuremath{\Delta}(1232)$ resonance were measured at TRIUMF using the CHAOS spectrometer and a polarized spin target. This work presents ${\ensuremath{\pi}}^{\ensuremath{-}}$ data at six incident energies of 57, 67, 87, 98, 117, and 139 MeV, and a single ${\ensuremath{\pi}}^{+}$ data set at 139 MeV. The higher energy measurements cover an angular range of $72\ifmmode^\circ\else\textdegree\fi{}<~{\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}<~180\ifmmode^\circ\else\textdegree\fi{}$ while the lower energies were limited to $101\ifmmode^\circ\else\textdegree\fi{}<~{\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}<~180\ifmmode^\circ\else\textdegree\fi{}.$ There is a high degree of consistency between this work and the predictions of the VPI/GWU group's SM95 partial wave analysis.