CLAS physics database search results Measurement E151M1176 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.65 270 -0.1547 0.8901 0.0321 0.75 186 -0.3617 0.8271 0.04 0.75 198 -0.0048 0.883 0.03 0.75 210 -0.836 0.8058 0.0681 0.75 222 -1.3527 0.7166 0.1033 0.75 270 1.1481 0.9416 0.0891 0.75 282 -0.4886 0.7886 0.0466 0.85 90 -0.4573 0.61 0.0449 0.85 102 0.5457 0.756 0.0499 0.85 114 0.3984 0.8647 0.0418 0.85 126 -1.0072 0.8125 0.0795 0.85 174 -0.6919 0.8214 0.0588 0.85 186 1.1865 0.9311 0.0918 0.85 198 -0.4405 0.6366 0.044 0.85 210 -0.0429 0.7827 0.0302 0.85 222 0.8405 0.9259 0.0684 0.85 234 0.0725 0.7701 0.0305 0.95 198 1.3954 0.9977 0.1063 0.95 222 -0.6655 0.7463 0.0571