CLAS physics database search results Measurement E159M54 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Data errors deg mcb/rad mcb/rad 30 0.469262 0.0682953 90 0.696029 0.0930429 150 0.737672 0.0996314 210 0.795289 0.1062 270 0.620093 0.0849043 330 0.480805 0.0697867