CLAS physics database search results Measurement E151M2714 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LU Stat. error Syst. error degrees 0.75 138 -0.3774 0.3547 0.0309 0.75 246 -0.1081 0.4111 0.0301 0.85 102 -0.1243 0.3602 0.0301 0.85 114 -0.4863 0.431 0.0315 0.85 282 -0.4278 0.2992 0.0312 0.65 294 -0.0222 0.285 0.03 0.85 102 0.1699 0.248 0.0302 0.85 126 0.1816 0.2493 0.0302 0.85 162 -0.0883 0.2604 0.0301 0.85 270 -0.373 0.2524 0.0309 0.85 294 -0.1785 0.2738 0.0302