CLAS physics database search results Measurement E151M105 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Data errors Systematic errors degrees 0.45 42 0.5861 0.7861 0.0731 0.45 54 -0.9759 0.6905 0.115 0.55 42 -0.5338 0.7736 0.0677 0.55 54 0.1184 0.7892 0.0329 0.55 222 1.1613 0.8319 0.1355 0.55 234 -0.302 0.6649 0.0456 0.55 246 -0.3066 0.714 0.046 0.65 30 2.0084 0.8212 0.2305 0.65 42 0.6565 0.8012 0.0805 0.65 54 -0.6291 0.7337 0.0776 0.65 234 -0.1171 0.5314 0.0328 0.65 246 0.6764 0.5853 0.0826 0.75 222 0.4044 0.6928 0.0549 0.75 234 0.1622 0.5745 0.0352 0.75 246 -0.6437 0.5749 0.0791 0.75 258 -1.1012 0.6094 0.1288 0.85 222 0.5567 0.7212 0.0701 0.85 234 1.1673 0.678 0.1362 0.85 246 0.4704 0.5852 0.0614