CLAS physics database search results Measurement E151M922 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.45 270 0.7074 0.5998 0.0553 0.65 78 0.4505 0.5934 0.0421 0.65 126 -0.7793 0.4921 0.0593 0.65 210 0.5404 0.6975 0.0464 0.75 210 0.6777 0.6674 0.0536 0.75 234 1.3794 0.6661 0.0954 0.75 270 0.9267 0.5994 0.0678 0.75 282 -0.1001 0.5496 0.0307 0.85 102 -0.6517 0.5803 0.0522 0.85 114 -0.3308 0.5663 0.037 0.85 126 -0.3405 0.6688 0.0374 0.85 210 -0.4915 0.6752 0.044 0.85 222 -0.083 0.6312 0.0305 0.45 282 -0.9339 1.2882 0.0913 0.65 126 0.1554 1.7187 0.0333 0.65 198 0.7819 1.8013 0.0782 0.75 210 -3.0046 1.41 0.2789 0.75 234 -0.4239 1.6047 0.0493 0.75 270 1.3681 1.6973 0.1298 0.75 282 1.4022 1.2975 0.1328 0.75 294 -0.1779 1.5794 0.0342 0.85 102 -0.0482 1.9857 0.0303 0.85 114 3.7983 1.8663 0.3518 0.85 210 1.0311 2.0773 0.0998