CLAS physics database search results Measurement E151M1231 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.45 282 0.6213 0.4753 0.0762 0.55 258 -0.6421 0.4608 0.0784 0.55 270 -0.3624 0.4161 0.0507 0.55 282 -0.444 0.4692 0.0584 0.65 258 0.0735 0.4213 0.0311 0.65 270 -0.6018 0.3156 0.0742 0.75 246 -0.0998 0.5287 0.032 0.75 258 0.499 0.4485 0.0638 0.75 270 -0.6418 0.4138 0.0784 0.85 138 0.3974 0.5854 0.0539 0.85 150 -0.6325 0.4535 0.0774 0.85 162 -0.1855 0.5131 0.0366 0.85 174 -0.3625 0.3673 0.0507 0.85 186 -0.0937 0.3875 0.0318 0.85 198 0.0027 0.364 0.03 0.85 210 -0.0686 0.4983 0.031 0.85 222 -0.0087 0.4907 0.03 0.95 174 0.8588 0.3987 0.1014