CLAS physics database search results Measurement E151M362 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Data errors Systematic errors degrees 0.65 138 0.5698 0.7185 0.0463 0.65 234 0.8723 0.7154 0.0618 0.65 246 -0.3632 0.6625 0.0375 0.75 138 -1.1372 0.681 0.0765 0.75 222 0.4954 0.6995 0.0429 0.75 246 -1.057 0.5768 0.072 0.75 258 -0.3713 0.6801 0.0378 0.85 258 0.7575 0.6938 0.0557 0.85 270 0.1361 0.6936 0.0312 0.95 90 -0.665 0.5786 0.0509 0.55 246 0.7724 1.214 0.0554 0.65 246 -0.1816 0.7702 0.0319 0.65 258 -0.7873 0.6053 0.0561 0.75 138 0.9019 1.3243 0.062 0.75 222 2.1107 1.262 0.1306 0.75 234 0.8695 1.1926 0.0603 0.75 246 -0.3268 0.8407 0.0359 0.85 246 0.9139 1.1304 0.0627 0.85 258 -0.1271 0.8173 0.031 0.85 270 0.1236 0.83 0.0309