CLAS physics database search results Measurement E151M1626 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.65 210 -1.1237 0.9895 0.0719 0.65 222 -1.2364 0.9812 0.0779 0.65 234 -0.2202 1.1496 0.0326 0.75 222 1.5279 0.8524 0.0938 0.75 234 -2.2855 2.2855 0.1362 0.85 222 -0.6117 1.0268 0.0465 0.45 42 -1.8353 0.9518 0.114 0.45 222 -0.4091 0.9511 0.0387 0.55 42 -0.3691 0.8083 0.0373 0.55 150 -0.8211 0.9346 0.0576 0.65 222 -0.1086 0.9258 0.0307 0.65 234 -0.5258 0.8962 0.0435 0.75 210 -0.0506 0.9793 0.0302 0.75 234 -1.2225 0.8102 0.0792 0.85 222 -1.0224 0.8052 0.0682