CLAS physics database search results Measurement E159M18 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Data errors deg mcb/rad mcb/rad 30 0.188051 0.0325755 90 0.475293 0.0661917 150 0.377836 0.0546694 210 0.397577 0.0578358 270 0.368112 0.0536678 330 0.20436 0.034448