CLAS physics database search results Measurement E159M954 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Data errors deg mcb/rad mcb/rad 30 0.0965414 0.020854 90 0.162322 0.0282727 150 0.152834 0.0278173 210 0.170525 0.031304 270 0.141008 0.0239889 330 0.0952368 0.0213511