CLAS physics database search results Measurement E151M1095 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.85 54 -1.0066 0.6944 0.0795 0.85 66 1.3517 1.0304 0.1033 0.85 210 -0.2023 0.8072 0.0334 0.85 222 0.7558 0.9459 0.0629 0.85 246 -0.1681 0.7893 0.0324 0.85 258 0.6323 0.7987 0.0551 0.85 270 1.7363 0.9466 0.1304 0.85 282 1.2171 0.8417 0.0939 0.85 294 -0.5318 0.7647 0.0491 0.95 270 0.7462 0.8315 0.0622 0.95 282 1.4263 0.9045 0.1085 0.95 294 0.4529 0.8375 0.0447 0.95 306 0.4174 0.725 0.0428 0.95 318 -0.7327 0.6252 0.0614