CLAS physics database search results Measurement E159M810 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Data errors deg mcb/rad mcb/rad 30 0.327849 0.054806 90 0.318931 0.0489251 150 0.370126 0.0564076 210 0.40803 0.0654435 270 0.316303 0.0521536 330 0.33664 0.0553465