CLAS physics database search results Measurement E151M2866 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LU Stat. error Syst. error degrees 0.55 210 0.5379 0.2306 0.0319 0.65 222 0.0773 0.2691 0.03 0.75 222 -0.2847 0.2292 0.0305 0.85 210 -0.1997 0.2623 0.0303 0.45 42 -0.0076 0.3874 0.03 0.65 222 -0.5139 0.2632 0.0317 0.75 210 -0.3444 0.355 0.0308 0.75 222 0.5131 0.2759 0.0317 0.85 222 -0.0558 0.4017 0.03