CLAS physics database search results Measurement E151M445 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.65 210 0.2591 1.2982 0.0338 0.65 222 0.0605 1.0601 0.0302 0.75 222 -1.2599 0.6074 0.0816 0.75 234 1.3884 1.1356 0.0888 0.85 222 0.7403 1.2188 0.0537 0.85 234 0.9167 1.1723 0.0628 0.85 246 -0.7088 0.6395 0.0522 0.65 234 -0.2406 0.6431 0.0335 0.75 234 -0.7458 0.6618 0.0551 0.85 222 -0.2839 0.633 0.0348 0.85 234 0.4503 0.5906 0.041