CLAS physics database search results Measurement E159M657 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Stat. error deg mcb/rad mcb/rad 30 0.0362107 0.00945987 90 0.070516 0.0146692 150 0.0718588 0.0132176 210 0.0938588 0.0178305 270 0.0869434 0.0159094 330 0.0549658 0.011752