CLAS physics database search results Measurement E151M1187 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.65 54 1.8402 1.0435 0.1378 0.65 282 0.0097 0.849 0.03 0.75 102 -0.7366 0.7512 0.0616 0.75 198 1.9152 0.9055 0.1432 0.75 210 -0.5325 0.818 0.0491 0.75 258 -0.3966 0.8699 0.0417 0.75 282 -0.6814 0.7832 0.0581 0.85 90 0.9004 0.9884 0.0723 0.85 102 1.3564 0.824 0.1036 0.85 114 -0.5999 0.7373 0.0531 0.85 126 1.1087 1.0972 0.0864 0.85 186 0.8301 0.7314 0.0677 0.85 198 -0.4184 0.6922 0.0428 0.85 210 -0.1156 0.7174 0.0312 0.85 222 -0.823 0.6725 0.0672 0.85 234 0.7717 0.9834 0.0639 0.95 210 0.4509 0.8465 0.0446