CLAS physics database search results Measurement E159M883 E1-6 V. Burkert 2001 psi(pi+) dsigma/dpsi_pip Data errors deg mcb/rad mcb/rad 30 0.0570698 0.0134719 90 0.0710616 0.0144488 150 0.087127 0.0184776 210 0.0692029 0.0162219 270 0.0686163 0.0179429 330 0.063496 0.0147017