CLAS physics database search results Measurement E151M5 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Data errors Systematic errors degrees 0.35 42 -0.3516 0.4782 0.05 0.55 258 -0.1377 0.395 0.0338 0.55 270 -0.258 0.3367 0.042 0.55 282 -0.1993 0.3587 0.0376 0.65 246 -1.1345 0.2995 0.1325 0.65 258 0.2578 0.3242 0.042 0.65 270 -0.0704 0.3131 0.0311 0.75 162 -0.0036 0.4061 0.03 0.75 174 0.8923 0.3905 0.1059 0.75 186 0.6279 0.4743 0.0775 0.75 198 -0.2515 0.4091 0.0415 0.75 210 -0.4913 0.4233 0.0634 0.75 234 -0.5368 0.3908 0.068 0.75 246 0.2154 0.4175 0.0387 0.75 258 -0.1074 0.3935 0.0324 0.75 270 -0.0185 0.4345 0.0301 0.85 162 0.2213 0.3808 0.0392 0.85 174 0.3825 0.3618 0.0529 0.85 186 0.0328 0.4563 0.0302 0.85 198 -0.484 0.3507 0.0627 0.85 210 -0.4279 0.4297 0.0572