CLAS physics database search results Measurement E151M664 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.65 114 0.3804 0.8591 0.038 0.65 222 0.3669 0.8268 0.0375 0.75 114 -0.0813 0.7223 0.0304 0.75 138 -0.6674 0.7453 0.0507 0.75 210 -0.0403 0.7927 0.0301 0.75 222 1.2148 0.8431 0.0801 0.75 234 1.0548 0.8675 0.0711 0.75 246 1.3455 0.8077 0.0876 0.85 78 -0.15 0.8342 0.0314 0.85 222 -0.3029 0.6857 0.0353 0.85 234 -0.4189 0.6398 0.0395 0.85 246 1.0869 0.8306 0.0729 0.85 258 0.1477 0.7922 0.0313 0.95 246 0.2218 0.6712 0.0329 0.95 258 -0.048 0.642 0.0301 0.95 270 0.3537 0.6596 0.037