CLAS physics database search results Measurement E159M20 E1-6 V. Burkert 2001 psi(p) dsigma/dpsi_pr Data errors deg mcb/rad mcb/rad 30 0.307343 0.0600395 90 0.449474 0.0761256 150 0.37819 0.0644814 210 0.392485 0.0665072 270 0.419701 0.0723576 330 0.340349 0.0627617