CLAS physics database search results Measurement E151M327 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Data errors Systematic errors degrees 0.65 258 0.4965 0.9841 0.0424 0.75 126 0.0399 1.107 0.0301 0.75 258 -0.7914 0.688 0.0563 0.75 270 -0.4096 0.7271 0.0388 0.85 282 -0.1667 0.8017 0.0316 0.85 294 -0.2021 0.9193 0.0324 0.55 258 0.1362 0.6402 0.0312 0.75 246 -0.2606 0.6581 0.0341 0.75 258 -1.1053 0.6345 0.0747 0.75 270 -0.525 0.6794 0.0442 0.75 282 -0.5351 0.6515 0.0447 0.85 282 -0.9535 0.5534 0.0662 0.85 294 0.1264 0.6269 0.031 0.95 78 -0.0516 0.5157 0.0302 0.95 258 -0.501 0.5329 0.0432 0.95 270 -0.3636 0.5242 0.0375 0.95 294 0.0333 0.5372 0.0301