CLAS physics database search results Measurement E151M1651 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 222 -0.6363 1.2864 0.0476 0.65 150 0.6558 1.0491 0.0485 0.65 222 -1.1098 1.2992 0.0712 0.65 234 0.7447 1.1963 0.0527 0.65 246 1.0626 1.1869 0.0687 0.75 222 -0.8531 1.0294 0.058 0.75 234 -0.404 1.1655 0.0381 0.75 246 2.6092 2.6092 0.1547 0.85 222 1.5851 0.9137 0.0969 0.85 234 0.2401 0.8606 0.0331 0.55 234 -0.0626 0.9696 0.0302 0.65 150 -0.089 0.9396 0.0305 0.65 222 -0.5191 0.8917 0.0432 0.65 234 0.2539 0.8838 0.0336 0.75 234 0.9552 0.8702 0.0646 0.75 246 -0.2445 0.8151 0.0334 0.85 138 0.1761 0.9 0.0318 0.85 222 -0.2635 0.8235 0.0339 0.85 246 -0.6854 0.9232 0.0509