CLAS physics database search results Measurement E151M2408 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.75 102 1.2358 1.0458 0.0945 0.75 114 -0.3243 1.0757 0.0381 0.75 198 -0.9655 1.0495 0.0762 0.75 210 -2.3969 0.7488 0.1764 0.75 222 0.9222 0.9993 0.0733 0.75 270 1.5085 0.9081 0.1134 0.75 282 0.7074 0.9778 0.0594 0.85 90 0.3847 0.9887 0.041 0.85 102 -0.4483 0.81 0.0442 0.85 114 0.0465 0.8644 0.0302 0.85 126 0.7159 1.042 0.06 0.85 186 -1.3201 0.8191 0.1003 0.85 198 0.3023 0.8869 0.0372 0.85 210 -0.073 0.8835 0.0305 0.85 222 0.3033 0.9104 0.0372 0.85 270 0.8529 1.0777 0.0687 0.95 210 0.7378 1.0152 0.0613