CLAS physics database search results Measurement E151M2791 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LU Stat. error Syst. error degrees 0.55 222 -0.1369 0.2693 0.0301 0.55 234 -0.4033 0.1338 0.0329 0.65 138 0.6705 0.2742 0.0329 0.65 222 0.0514 0.2865 0.03 0.65 234 -0.0434 0.21 0.0303 0.75 162 -0.3938 0.3204 0.031 0.75 222 -0.3059 0.3991 0.0306 0.75 234 0.5364 0.2284 0.0319 0.85 210 0.0257 0.3835 0.03 0.85 222 -0.1491 0.3419 0.0301 0.85 234 0.3947 0.3219 0.031 0.65 246 -0.3547 0.2585 0.0308 0.75 234 -0.4782 0.2067 0.0315 0.75 246 -0.1226 0.2818 0.0301 0.85 234 -0.18 0.273 0.0302