CLAS physics database search results Measurement E151M429 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Data errors Systematic errors degrees 0.55 222 -0.7189 0.8551 0.0527 0.65 150 -1.9549 0.4409 0.1215 0.65 222 0.8336 1.2553 0.0585 0.65 234 1.7962 1.4642 0.1122 0.65 246 0.9744 1.2136 0.0659 0.75 222 2.2162 1.2589 0.1368 0.75 234 1.9397 1.3681 0.1206 0.75 246 -0.6082 1.5315 0.0473 0.85 222 1.9365 1.3307 0.1204 0.85 234 -0.5484 0.6186 0.0446 0.55 234 0.6453 0.7236 0.05 0.65 150 -1.2102 0.6908 0.0807 0.65 222 -0.3017 0.6881 0.0353 0.65 234 0.2365 0.6719 0.0334 0.75 234 0.7699 0.6465 0.0563 0.75 246 -0.2119 0.6245 0.0327 0.85 138 -1.1825 0.6601 0.0791 0.85 222 -0.6699 0.6248 0.0512 0.85 246 0.4552 0.7021 0.0412