CLAS physics database search results Measurement E151M251 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Data errors Systematic errors degrees 0.75 114 -0.3966 0.5619 0.0388 0.85 102 -0.7469 0.5386 0.0551 0.55 270 0.5255 0.987 0.0436 0.85 102 0.2845 0.8888 0.0345 0.85 114 0.4986 1.0846 0.0424 0.85 150 0.1143 0.8769 0.0308 0.85 270 0.7956 0.9005 0.0565 0.85 294 -0.4903 0.6288 0.0421 0.95 138 0.6962 0.9107 0.0516