CLAS physics database search results Measurement E159M839 E1-6 V. Burkert 2001 psi(p) dsigma/dpsi_pr Data errors deg mcb/rad mcb/rad 30 0.346382 0.0650724 90 0.343717 0.0628303 150 0.414019 0.0813826 210 0.436012 0.0850721 270 0.400117 0.0815665 330 0.394715 0.0724199