CLAS physics database search results Measurement E151M702 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.45 282 1.0858 0.6135 0.0729 0.65 126 0.4307 0.7064 0.0399 0.65 198 0.1629 0.6582 0.0316 0.65 282 0.1529 0.6311 0.0314 0.65 294 -0.0041 0.587 0.03 0.75 198 -0.6111 0.477 0.0479 0.75 210 0.237 0.5518 0.0333 0.75 222 -0.5218 0.4627 0.0438 0.75 282 -0.3149 0.4556 0.0356 0.85 114 0.284 0.5534 0.0347 0.85 234 0.4 0.6446 0.0387