CLAS physics database search results Measurement E151M1870 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.65 114 0.6714 0.9189 0.0505 0.65 126 0.2041 0.9763 0.0324 0.65 222 -0.4893 0.9062 0.0422 0.65 294 -0.0679 0.8577 0.0303 0.75 102 -0.7166 0.9304 0.0528 0.75 126 0.0871 0.8614 0.0305 0.75 222 0.2377 0.8049 0.0333 0.75 246 -1.4899 0.7352 0.0951 0.85 222 -0.3034 0.7139 0.0352 0.85 234 -0.9038 0.6433 0.0624 0.85 246 -0.7073 0.7886 0.0523 0.85 258 1.4009 0.6943 0.09 0.85 270 -0.4522 0.8792 0.0406 0.95 210 -0.0773 0.7612 0.0304 0.95 246 -0.5899 0.693 0.0467 0.95 270 -0.3326 0.6993 0.0361