CLAS physics database search results Measurement E151M1607 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 42 -0.0645 0.7766 0.0302 0.65 138 -0.231 0.8285 0.033 0.65 150 0.1011 0.799 0.0306 0.65 222 -0.2707 0.8264 0.0341 0.75 210 -0.957 0.6999 0.0647 0.75 222 -0.5487 0.8225 0.0445 0.75 234 0.4551 0.8638 0.0405 0.85 222 -1.2295 0.7481 0.0796 0.85 234 -1.3354 0.7672 0.0855 0.55 222 -0.8479 0.9634 0.0577 0.65 138 -2.361 2.361 0.1405 0.65 210 -1.3897 0.856 0.0862 0.65 222 1.4502 0.5835 0.0895 0.65 234 -0.0804 0.981 0.0304 0.75 210 -1.2462 0.7911 0.0784 0.75 222 1.7677 0.688 0.1071 0.75 234 -1.0698 0.7649 0.0691 0.85 234 0.1899 0.9313 0.032