CLAS physics database search results Measurement E159M739 E1-6 V. Burkert 2001 psi(pi+) dsigma/dpsi_pip Data errors deg mcb/rad mcb/rad 30 0.23945 0.0405569 90 0.178813 0.0286809 150 0.340131 0.0505994 210 0.365156 0.0549853 270 0.260061 0.0431096 330 0.217997 0.0357691