CLAS physics database search results Measurement E151M663 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.55 114 0.3649 0.8507 0.0374 0.65 114 -0.7394 0.7408 0.0543 0.75 114 0.7466 0.8856 0.0546 0.75 126 -1.0088 0.6806 0.0686 0.75 210 1.1555 0.7683 0.0768 0.75 222 -1.1522 0.6401 0.0766 0.75 246 2.9008 2.9008 0.1799 0.85 90 1.158 0.7098 0.0769 0.85 102 -1.4857 0.5799 0.0957 0.85 234 0.8235 0.6842 0.0586 0.85 246 0.2081 0.7773 0.0326 0.85 258 3.3918 3.3918 0.2096 0.95 222 -0.6117 0.6278 0.048 0.95 234 -0.0805 0.6849 0.0304 0.95 258 -0.9521 0.5563 0.0655