CLAS physics database search results Measurement E151M440 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.65 150 2.129 1.5257 0.1317 0.65 222 2.062 1.3596 0.1277 0.65 234 -1.4528 0.4865 0.0925 0.75 222 -0.7774 0.6752 0.0556 0.85 222 3.7088 3.7088 0.2253 0.35 42 -1.0782 0.659 0.0732 0.75 222 1.1844 0.5808 0.0792 0.85 150 -0.5837 0.7036 0.047 0.85 234 0.2509 0.6172 0.0338