CLAS physics database search results Measurement E151M1695 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 78 0.7847 0.5586 0.0562 0.55 90 0.227 0.6218 0.033 0.65 90 -0.0019 0.5743 0.03 0.65 258 -1.0255 0.4685 0.069 0.65 270 0.6479 0.4974 0.0494 0.75 126 0.04 0.6104 0.0301 0.75 246 0.3632 0.5523 0.0372 0.75 258 -0.2774 0.4175 0.0344 0.75 270 -0.4818 0.5081 0.0419 0.85 126 -0.1138 0.611 0.0308 0.85 138 1.1438 0.4827 0.0755 0.85 150 -0.5363 0.4969 0.0442 0.85 174 -0.812 0.5525 0.0576 0.85 246 0.9209 0.5586 0.0634 0.95 150 0.2108 0.5874 0.0326 0.95 162 -0.3047 0.5422 0.0352