CLAS physics database search results Measurement E159M820 E1-6 V. Burkert 2001 psi(pi+) dsigma/dpsi_pip Data errors deg mcb/rad mcb/rad 30 0.4065 0.0693327 90 0.354085 0.0566963 150 0.422909 0.0656038 210 0.443016 0.0719581 270 0.369948 0.0599992 330 0.372486 0.0610744