CLAS physics database search results Measurement E151M457 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.75 222 0.7882 0.6364 0.0573 0.75 246 1.5904 0.6535 0.1029 0.65 234 -0.9538 0.7172 0.0648 0.75 234 1.7335 1.4375 0.1086 0.85 222 0.7295 1.1999 0.0532