CLAS physics database search results Measurement E159M270 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Data errors deg mcb/rad mcb/rad 30 0.402824 0.0548519 90 0.525953 0.0682343 150 0.560591 0.0738306 210 0.525596 0.0693776 270 0.512429 0.0690112 330 0.374187 0.0523501