CLAS physics database search results Measurement E159M837 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Data errors deg mcb/rad mcb/rad 30 0.388674 0.0715241 90 0.367408 0.057749 150 0.39972 0.062229 210 0.417439 0.0700556 270 0.316756 0.0541622 330 0.319174 0.0541216