CLAS physics database search results Measurement E151M2166 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.35 294 -0.1784 0.7419 0.0327 0.45 294 1.1364 0.6917 0.0877 0.55 282 0.3171 0.7077 0.0378 0.55 294 -0.2836 0.6109 0.0364 0.65 270 0.3412 0.6782 0.0389 0.65 282 -0.7245 0.6528 0.0605 0.65 294 -0.3907 0.505 0.0413 0.75 66 -0.2324 0.6812 0.0344 0.75 78 0.0681 0.6697 0.0304 0.75 90 0.6195 0.6396 0.054 0.75 270 -0.0767 0.7758 0.0305 0.75 282 0.4048 0.6721 0.042 0.75 294 1.1639 0.5102 0.0896 0.85 54 0.4018 0.7487 0.0418 0.85 66 -0.0197 0.5227 0.03 0.85 78 0.411 0.5123 0.0423 0.85 90 -0.3789 0.6396 0.0407 0.85 102 -0.3242 0.6672 0.0381 0.85 306 0.0902 0.7068 0.0307 0.95 42 1.1377 0.574 0.0878 0.95 54 0.5738 0.6355 0.0513 0.95 102 -0.2688 0.6342 0.0358