CLAS physics database search results Measurement E151M2695 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LU Stat. error Syst. error degrees 0.75 114 0.3047 0.2524 0.0306 0.85 102 0.1429 0.264 0.0301 0.55 270 0.366 0.4308 0.0309 0.85 102 0.0621 0.3706 0.03 0.85 114 -0.4838 0.4067 0.0315 0.85 150 0.6629 0.2187 0.0328 0.85 270 0.3373 0.2985 0.0307 0.85 294 -0.3424 0.3544 0.0308 0.95 138 -0.5457 0.2624 0.0319