CLAS physics database search results Measurement E151M161 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Data errors Systematic errors degrees 0.55 246 0.7303 0.7447 0.0883 0.55 258 -0.2596 0.7577 0.0421 0.55 270 -0.2776 0.6932 0.0436 0.65 150 -0.0296 0.862 0.0302 0.65 222 0.4859 0.8326 0.0629 0.65 234 1.1111 0.796 0.1299 0.65 246 0.0339 0.6885 0.0302 0.65 258 -0.3416 0.5616 0.0491 0.65 270 -0.7993 0.6571 0.0958 0.75 150 -0.5341 0.8406 0.0678 0.75 162 0.9283 0.92 0.1098 0.75 234 0.4217 0.6829 0.0566 0.75 246 -0.245 0.7062 0.0409 0.75 258 0.7579 0.7104 0.0913 0.75 270 0.0765 0.7106 0.0312 0.85 234 1.2201 0.7739 0.142 0.85 246 1.3317 0.6823 0.1544 0.85 258 -0.15 0.704 0.0345 0.85 270 0.0944 0.6525 0.0319 0.85 282 -1.4739 0.5522 0.1704