CLAS physics database search results Measurement E151M2121 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.65 126 -1.2619 0.7931 0.1198 0.65 282 0.3615 0.8128 0.0448 0.65 294 -1.6831 0.6397 0.1576 0.75 282 -0.7032 0.6012 0.0713 0.75 294 0.5844 0.7951 0.0615 0.85 102 0.7936 0.9903 0.0789 0.85 114 0.3247 1.1301 0.0423 0.85 246 -0.889 0.9362 0.087 0.55 282 -1.0178 0.7032 0.0727 0.65 114 0.6884 0.8682 0.0539 0.65 210 0.5911 0.9531 0.0488 0.65 222 0.1077 0.9988 0.0308 0.65 294 -0.8913 0.6739 0.0653 0.75 126 -0.7676 0.8984 0.0583 0.75 222 0.0911 0.8317 0.0306 0.75 234 0.1567 0.914 0.0317 0.75 282 1.0203 0.7176 0.0728 0.85 102 -0.6121 0.9268 0.0499 0.85 114 -1.637 0.8416 0.1106 0.85 222 1.669 0.8983 0.1126 0.85 234 -0.7486 0.9714 0.0572 0.95 246 1.2846 1.4574 0.0888