CLAS physics database search results Measurement E151M1645 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 30 -0.6058 1.1634 0.0463 0.55 222 -0.9143 1.0227 0.061 0.55 234 -1.1114 1.1284 0.0712 0.65 150 -0.1654 1.3005 0.0315 0.65 222 0.2918 1.0509 0.0345 0.75 222 -1.0373 0.9441 0.0674 0.75 234 -0.7894 1.2116 0.0548 0.85 138 1.0934 1.0574 0.0703 0.85 222 -0.553 0.999 0.044 0.85 234 -0.5182 0.9848 0.0425 0.45 30 0.6223 0.9444 0.0479 0.55 42 0.6565 0.9394 0.0495 0.55 210 -0.1549 0.7889 0.0314 0.55 234 -0.1689 0.9791 0.0317 0.65 138 -0.1726 0.9145 0.0317 0.75 234 0.1303 0.879 0.031