CLAS physics database search results Measurement E151M635 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.65 114 -0.3544 0.75 0.037 0.75 102 -1.2292 0.6305 0.0809 0.75 246 0.3104 0.7642 0.0355 0.75 258 1.5678 0.939 0.1005 0.85 234 2.0276 0.7449 0.1276 0.85 246 -0.2012 0.609 0.0324 0.85 258 -0.1559 0.6344 0.0315 0.95 78 0.4674 0.7591 0.0414 0.95 258 0.4236 0.7207 0.0396 0.95 270 0.6216 0.6962 0.0484 0.95 282 0.1819 0.5635 0.032 0.95 294 0.6332 0.6917 0.049