CLAS physics database search results Measurement E151M1934 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.45 270 -1.7097 0.6956 0.1079 0.55 270 1.2333 0.8586 0.0805 0.65 126 -1.0113 0.8093 0.0682 0.65 138 -2.0187 0.6585 0.1259 0.65 198 -2.2134 2.2134 0.1374 0.65 222 0.6582 0.7811 0.0499 0.75 66 0.3613 0.8604 0.0371 0.75 210 -1.0316 0.7903 0.0693 0.75 270 -0.7106 0.6386 0.0525 0.75 282 -0.371 0.7373 0.0375 0.85 114 -0.1448 0.8595 0.0313 0.85 126 -0.3441 0.6453 0.0365 0.85 138 -0.5471 0.7915 0.0447 0.85 198 0.9917 0.8052 0.0672 0.85 210 0.0153 0.8661 0.03 0.85 222 -0.4428 0.7816 0.0402