CLAS physics database search results Measurement E151M854 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.65 102 -1.0682 0.4268 0.0762 0.75 102 -0.2626 0.5835 0.0346 0.75 234 0.355 0.647 0.038 0.85 78 0.6669 0.6693 0.0531 0.85 234 2.0906 0.7653 0.1404 0.85 270 -0.4356 0.605 0.0414 0.65 126 0.7629 1.7003 0.0765 0.75 102 -0.7783 1.5424 0.0778 0.75 222 0.2099 1.5102 0.0357 0.75 234 -2.0582 1.1407 0.1923 0.85 234 2.5116 1.8182 0.2337 0.85 258 0.1537 1.5425 0.0332