CLAS physics database search results Measurement E159M639 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Stat. error deg mcb/rad mcb/rad 30 0.443169 0.0714694 90 0.435386 0.0689161 150 0.521316 0.0788859 210 0.51823 0.0817449 270 0.42105 0.0631856 330 0.414106 0.066196