CLAS physics database search results Measurement E151M1897 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.45 270 -0.5059 0.9009 0.0429 0.55 126 1.4473 0.8265 0.0927 0.55 270 -0.6952 0.7883 0.0517 0.55 282 -0.4303 0.8285 0.0397 0.65 126 0.3826 0.7774 0.0379 0.65 138 -0.8148 0.9286 0.0578 0.65 222 0.4106 0.818 0.039 0.65 294 0.7249 0.8551 0.0532 0.75 138 0.1459 0.8913 0.0313 0.75 198 -1.4958 0.6745 0.0955 0.75 210 -0.7622 0.7827 0.0551 0.75 222 -0.9548 0.698 0.0652 0.75 270 -0.1998 0.8144 0.0324 0.75 282 -0.6444 0.7757 0.0492 0.75 294 -0.7888 0.8661 0.0564 0.85 102 -0.3727 0.9194 0.0376 0.85 114 0.044 0.7895 0.0301 0.85 198 1.045 0.8491 0.0701 0.85 210 0.1264 0.8661 0.031 0.85 222 -1.4044 0.7028 0.0902 0.85 234 -1.4974 0.7135 0.0956 0.95 222 1.5417 0.65 0.0981