CLAS physics database search results Measurement E151M2076 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.65 102 0.0975 0.6037 0.0307 0.75 102 -0.4967 0.7027 0.0441 0.75 234 -1.206 0.6698 0.084 0.85 78 -0.5274 0.7404 0.0456 0.85 234 -0.5622 0.8702 0.0473 0.85 270 -1.232 0.6831 0.0856 0.65 126 -1.0956 1.9049 0.1051 0.75 102 -0.7283 1.8335 0.0734 0.75 222 0.5327 1.7498 0.0574 0.75 234 2.7309 1.4544 0.2528 0.85 234 2.4642 1.9765 0.2284 0.85 258 -0.3026 1.7887 0.0409