CLAS physics database search results Measurement E151M1184 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.75 102 -1.006 0.8014 0.0794 0.75 114 -0.1874 0.8684 0.033 0.75 186 -0.7181 0.8979 0.0605 0.75 198 -0.0549 0.9156 0.0303 0.75 210 -0.2752 0.8901 0.0361 0.85 102 -0.886 0.7292 0.0714 0.85 114 0.722 0.841 0.0607 0.85 126 1.8315 0.9982 0.1372 0.85 174 1.7366 1.1266 0.1304 0.85 186 -1.4436 0.6847 0.1097 0.85 198 0.8888 0.8899 0.0716 0.85 210 -1.9774 0.5382 0.1476