CLAS physics database search results Measurement E159M468 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Data errors deg mcb/rad mcb/rad 30 0.242191 0.0478273 90 0.286436 0.0413095 150 0.36261 0.0537231 210 0.520545 0.0884736 270 0.309507 0.045007 330 0.255249 0.0457387