CLAS physics database search results Measurement E151M164 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Data errors Systematic errors degrees 0.45 42 -0.257 0.7149 0.0419 0.45 54 0.2259 0.6083 0.0395 0.45 222 0.743 0.8379 0.0897 0.55 42 0.706 0.8176 0.0857 0.55 54 0.4295 0.7216 0.0573 0.55 222 1.3553 0.6832 0.1571 0.55 234 -0.132 0.673 0.0335 0.55 246 -0.7121 0.6347 0.0864 0.65 222 -0.2421 0.6004 0.0407 0.65 234 0.2028 0.7627 0.0378 0.65 246 0.179 0.624 0.0363 0.75 222 -0.4458 0.647 0.0589 0.75 234 -0.3191 0.5335 0.0471 0.75 246 0.2688 0.634 0.0428 0.85 222 -0.3302 0.6957 0.0481 0.85 234 0.8502 0.6784 0.1013