CLAS physics database search results Measurement E159M568 E1-6 V. Burkert 2001 psi(pi+) dsigma/dpsi_pip Data errors deg mcb/rad mcb/rad 30 0.542232 0.0778671 90 0.459103 0.0665494 150 0.634263 0.0931269 210 0.610492 0.0884249 270 0.514629 0.0741819 330 0.512915 0.0735552