CLAS physics database search results Measurement E151M1919 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.45 78 -1.2988 0.5971 0.0842 0.45 270 0.1298 0.7073 0.031 0.45 282 -0.3399 0.6049 0.0364 0.55 102 -0.5313 0.7337 0.044 0.55 258 -0.0887 0.7297 0.0305 0.55 270 -1.5563 0.6442 0.099 0.55 318 -0.708 0.6769 0.0524 0.65 126 -0.8022 0.5942 0.0571 0.65 198 -1.561 0.5778 0.0992 0.65 210 -0.1899 0.6782 0.0321 0.65 282 -0.0909 0.6249 0.0305 0.65 294 0.7857 0.6907 0.0563 0.75 66 0.3945 0.5766 0.0384 0.75 78 0.7896 0.7078 0.0565 0.75 198 0.5851 0.5873 0.0464 0.75 222 0.6504 0.5922 0.0495 0.75 258 -0.5 0.6654 0.0426 0.75 270 0.564 0.4722 0.0455 0.75 282 0.3964 0.4867 0.0384 0.85 114 1.0128 0.5929 0.0683 0.85 126 0.8607 0.6351 0.0602 0.85 138 -1.2729 0.5998 0.0828 0.85 198 -0.4504 0.5975 0.0406 0.85 210 -1.1494 0.5688 0.0758 0.85 222 -0.8997 0.5624 0.0622 0.85 270 -0.708 0.6416 0.0524