CLAS physics database search results Measurement E151M738 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.65 282 -0.3387 1.8817 0.0433 0.65 294 0.639 1.9965 0.0662 0.75 282 -0.9077 1.8062 0.089 0.85 78 0.4615 2.8965 0.0521 0.85 90 -0.2789 2.4811 0.0395 0.85 114 -5.5331 2.1793 0.5115 0.55 270 0.0578 0.4539 0.0302 0.55 282 -0.3578 0.393 0.0381 0.75 282 -0.3818 0.3609 0.0391 0.85 90 -0.0696 0.4421 0.0303 0.85 102 0.6598 0.5285 0.0527 0.85 282 -0.5445 0.411 0.0467