CLAS physics database search results Measurement E151M1238 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.35 282 -0.0863 0.5585 0.0315 0.45 282 -0.5518 0.4731 0.0691 0.45 294 -0.7743 0.5205 0.0923 0.55 270 -0.4606 0.4819 0.06 0.55 282 0.2845 0.4637 0.0439 0.55 294 -1.1142 0.4788 0.1292 0.65 270 -0.5166 0.4792 0.0655 0.65 282 -0.6308 0.433 0.0772 0.65 294 -0.1096 0.543 0.0324 0.75 270 -0.941 0.4577 0.1103 0.75 282 -0.3701 0.4338 0.0514 0.85 138 1.7531 1.7531 0.2 0.95 126 -0.4411 0.4617 0.0581 0.95 138 1.0547 0.394 0.1227 0.95 150 0.399 0.4074 0.0541 0.95 162 -0.1169 0.371 0.0328 0.95 174 0.151 0.3787 0.0345 0.95 186 0.8813 0.3844 0.1038 0.95 198 0.4443 0.4815 0.0584 0.95 210 -0.1535 0.4304 0.0346 0.95 222 -0.3892 0.464 0.0532