CLAS physics database search results Measurement E151M2388 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.65 210 -0.3811 1.0916 0.0408 0.65 282 0.2632 0.8761 0.0356 0.65 294 1.0312 0.8782 0.0806 0.75 90 0.2448 1.0917 0.0349 0.75 198 1.1554 1.1128 0.089 0.75 210 -1.2141 1.0516 0.093 0.75 222 1.1809 0.9779 0.0907 0.75 234 -0.8062 1.0917 0.0657 0.85 78 -0.2927 0.9796 0.0367 0.85 90 0.577 0.8871 0.0515 0.85 102 -0.3595 1.0316 0.0397 0.85 114 -0.1442 0.9465 0.0318 0.85 186 0.5529 1.0221 0.0501 0.85 198 -0.9935 0.8263 0.078 0.85 210 -0.1892 0.9242 0.033 0.85 222 -0.385 0.8742 0.041 0.85 234 -1.0167 0.905 0.0796 0.85 246 -1.4754 0.8759 0.1111 0.95 186 -1.1281 0.9419 0.0871 0.95 198 0.7052 0.9801 0.0593 0.95 210 -1.3078 0.9235 0.0995 0.95 222 -0.1406 0.9722 0.0317 0.95 234 -0.1773 0.9727 0.0326 0.95 246 1.2156 0.7638 0.0931