CLAS physics database search results Measurement E151M1665 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 210 0.5649 1.1596 0.0445 0.55 222 1.2082 1.1286 0.0764 0.75 222 -0.2743 0.9702 0.034 0.85 138 0.6178 1.237 0.0468 0.85 222 -0.6546 1.2214 0.0485 0.85 234 -0.1516 1.0299 0.0313 0.45 246 -0.7936 0.9257 0.0562 0.55 234 1.3113 0.8328 0.0841 0.75 210 -0.0925 1.0199 0.0305 0.75 234 -0.7256 0.9704 0.0528 0.85 138 -0.4611 0.9197 0.0408 0.85 234 -1.4389 0.8267 0.0913 0.85 246 -0.2093 0.8834 0.0325