CLAS physics database search results Measurement E151M2369 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.65 210 -1.2652 1.0219 0.0965 0.75 198 -0.7763 1.03 0.0638 0.75 210 0.4505 0.9356 0.0444 0.75 222 -0.3689 1.042 0.0402 0.75 282 -1.8748 0.9722 0.1392 0.85 90 1.5884 0.8585 0.119 0.85 102 0.4305 1.0242 0.0433 0.85 114 -1.4652 0.9269 0.1104 0.85 126 -1.8673 0.988 0.1387 0.85 186 0.0702 1.0575 0.0304 0.85 210 -0.7758 0.8671 0.0638 0.85 222 -1.164 1.0152 0.0896 0.85 234 -1.1523 0.9674 0.0888