CLAS physics database search results Measurement E151M441 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.55 210 0.7249 1.305 0.053 0.55 222 0.4378 0.6378 0.0407 0.65 222 1.9948 1.3993 0.1238 0.75 222 -0.2542 1.0116 0.0337 0.75 234 3.7756 3.7756 0.2293 0.85 222 0.2035 0.8705 0.0324 0.55 234 1.1115 0.7356 0.0751 0.75 30 -0.4008 0.6933 0.0389 0.75 222 0.4085 0.6779 0.0392 0.75 234 0.5338 0.7328 0.0446 0.85 222 0.1253 0.6441 0.031 0.85 234 0.9299 0.6879 0.0649