CLAS physics database search results Measurement E151M2008 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.75 90 0.5899 1.5446 0.062 0.75 246 -0.0134 1.3725 0.03 0.85 90 1.7845 1.6584 0.1667 0.85 102 4.1204 1.527 0.3799 0.95 306 10.2381 10.2381 0.9414 0.65 270 -1.6348 0.5768 0.1105 0.75 78 0.4947 0.6735 0.044 0.75 102 1.161 0.6463 0.0813 0.85 90 -0.3004 0.7144 0.0358 0.85 102 0.009 0.7157 0.03 0.85 114 -0.2065 0.7012 0.0329 0.85 246 0.1417 0.7831 0.0314 0.85 270 -0.2882 0.7347 0.0354 0.85 282 0.5664 0.6877 0.0475 0.85 294 0.5914 0.6155 0.0488 0.95 270 2.6565 0.8962 0.1754 0.95 294 0.9237 1.049 0.0672