CLAS physics database search results Measurement E151M1263 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 246 0.0264 0.6045 0.0301 0.65 234 0.0402 0.6765 0.0303 0.65 246 0.1579 0.533 0.0349 0.65 258 -0.1933 0.5482 0.0371 0.65 270 1.0615 0.6339 0.1234 0.75 246 -0.4289 0.5047 0.0569 0.75 258 0.5682 0.5639 0.0708 0.85 246 -0.3343 0.6644 0.0482