CLAS physics database search results Measurement E151M701 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.55 222 0.0529 0.6069 0.0302 0.65 138 0.5045 0.6316 0.043 0.65 222 1.6704 0.6431 0.1065 0.75 198 -0.0303 0.541 0.0301 0.75 210 0.6443 0.5848 0.0495 0.75 222 0.646 0.5944 0.0496 0.75 234 0.2785 0.5857 0.0345 0.75 270 0.46 0.5871 0.0411 0.75 282 0.2941 0.5276 0.035 0.85 114 -0.6804 0.5421 0.0513 0.85 126 -0.0188 0.5764 0.03 0.85 222 0.9082 0.5815 0.0631