CLAS physics database search results Measurement E151M3628 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LU Stat. error Syst. error degrees 0.75 102 0.6245 0.2639 0.0325 0.75 114 -0.1169 0.2556 0.0301 0.75 186 -0.0151 0.2911 0.03 0.75 198 0.1527 0.2645 0.0302 0.75 210 -0.0026 0.2651 0.03 0.85 102 0.6319 0.1918 0.0326 0.85 114 -0.0701 0.2221 0.03 0.85 126 0.3768 0.2128 0.0309 0.85 174 -0.0181 0.2705 0.03 0.85 186 -0.416 0.2316 0.0311 0.85 198 -0.2993 0.2244 0.0306 0.85 210 0.5343 0.2336 0.0318