Measurements of asymmetries of pion single charge exchange on polarized 3He at 200 MeV

Asymmetries for the (π^-,π⁰) reaction on polarized ³He were measured using a 200-MeV pion beam at LAMPF. The π⁰'s were detected with the neutral meson spectrometer in coincidence with the recoiling tritons. A recoil triton detector, consisting of scintillation-counter telescopes and a wire chamber, was used to measure the time-of-flight, energy loss, and direction of the tritons. The polarized gaseous ³He target, developed at TRIUMF, was modified to run with two diode lasers; the polarization reached 65%. The asymmetries between θ_lab=60° and 105° were found to be strongly angle dependent. The results are compared with theoretical calculations.