CLAS physics database search results Measurement E151M1654 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 222 -0.641 0.7593 0.0485 0.55 234 -1.8978 0.8067 0.1172 0.65 234 -0.8776 1.0164 0.0606 0.65 246 1.5532 0.9516 0.0978 0.75 138 0.5529 0.8646 0.0447 0.75 162 -0.2838 0.888 0.0345 0.75 222 -0.1038 0.9831 0.0306 0.75 246 -1.9345 0.7202 0.1198 0.85 222 -0.8384 0.9233 0.0585 0.85 234 0.8915 0.7879 0.0613 0.85 246 -0.0404 0.7498 0.0301 0.85 258 0.4327 0.9978 0.0397 0.95 138 -0.181 0.8294 0.0319 0.55 246 -1.082 1.1588 0.0697 0.65 222 -1.232 1.0219 0.0777 0.65 234 -2.1389 0.7168 0.1279 0.75 234 -1.0003 1.1804 0.0654 0.75 246 -1.8217 0.7015 0.1101 0.75 258 0.7865 1.1294 0.0547 0.85 234 0.0307 0.9606 0.0301 0.85 246 -1.1444 0.8439 0.073