CLAS physics database search results Measurement E159M172 E1-6 V. Burkert 2001 psi(pi+) dsigma/dpsi_pip Data errors deg mcb/rad mcb/rad 30 1.03613 0.153986 90 1.01702 0.161142 150 1.19488 0.176958 210 1.26079 0.187592 270 1.0706 0.164763 330 1.06127 0.160801