CLAS physics database search results Measurement E151M2505 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LU Stat. error Syst. error degrees 0.65 246 -0.2107 0.2191 0.0303 0.75 234 -0.47 0.2295 0.0314 0.75 246 0.1848 0.2295 0.0302 0.75 258 0.2317 0.2279 0.0304