Low Energy Analyzing Powers in Pion-Proton Elastic Scattering
  Analyzing powers of pion-proton elastic scattering have been measured at PSI with the Low Energy Pion Spectrometer LEPS as well as a novel polarized scintillator target. Angular distributions between 40 and 120 deg (c.m.) were taken at 45.2, 51.2, 57.2, 68.5, 77.2, and 87.2 MeV incoming pion kinetic energy for pi+ p scattering, and at 67.3 and 87.2 MeV for pi- p scattering. These new measurements constitute a substantial extension of the polarization data base at low energies. Predictions from phase shift analyses are compared with the experimental results, and deviations are observed at low energies. 
R. Meier, M. Cr\"oni, R. Bilger, B. van den Brandt, J. Breitschopf, H.   Clement, J. R. Comfort, H. Denz, A. Erhardt, K. F\"...