CLAS physics database search results Measurement E151M2389 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.75 198 0.4149 1.1366 0.0425 0.85 78 -0.1519 0.9763 0.032 0.85 102 0.6027 1.0975 0.053 0.85 186 0.4333 1.0933 0.0434 0.85 198 0.6289 0.965 0.0546 0.85 210 1.4101 0.8463 0.1066 0.85 222 1.1777 0.9153 0.0905 0.85 234 -1.2161 0.8411 0.0931 0.85 246 -0.3937 1.0299 0.0414 0.95 198 1.4603 1.0868 0.1101 0.95 210 -1.1326 0.7998 0.0874 0.95 222 -1.3689 0.8547 0.1037 0.95 234 0.8378 0.8675 0.0678 0.95 246 -1.0843 0.9108 0.0842