CLAS physics database search results Measurement E151M1195 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.75 198 2.4095 1.1395 0.1786 0.75 270 0.3752 0.8102 0.0406 0.85 102 1.1434 1.0007 0.0888 0.85 114 2.0711 0.8475 0.1543 0.85 186 -0.2682 0.9632 0.0358 0.85 198 -0.0138 0.8446 0.03 0.85 210 1.8343 1.08 0.1374 0.85 270 1.065 1.0086 0.0834