CLAS physics database search results Measurement E151M1057 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.55 90 -0.741 0.612 0.0619 0.65 78 1.136 0.8737 0.0883 0.65 90 -0.7519 0.608 0.0626 0.65 114 -0.3085 0.7827 0.0375 0.75 90 -0.1948 0.7235 0.0332 0.75 114 -1.3266 0.555 0.1015 0.75 246 0.3103 0.7901 0.0376 0.75 270 0.6119 0.8123 0.0539 0.85 54 0.0754 0.8188 0.0305 0.85 102 -0.7169 0.649 0.0604 0.85 222 1.0315 0.8026 0.0811 0.85 234 1.4156 0.8093 0.1077 0.85 246 0.1815 0.7818 0.0328 0.85 270 -0.5973 0.6047 0.053 0.85 282 1.0894 0.81 0.0851 0.85 294 0.7322 0.6768 0.0614 0.85 306 -0.1586 0.7061 0.0322 0.95 294 -0.0063 0.5548 0.03 0.95 306 -0.0883 0.6091 0.0307