CLAS physics database search results Measurement E159M748 E1-6 V. Burkert 2001 psi(pi+) dsigma/dpsi_pip Data errors deg mcb/rad mcb/rad 30 0.278399 0.0418778 90 0.31272 0.0499412 150 0.461332 0.0737229 210 0.446841 0.0651145 270 0.293868 0.0474919 330 0.276822 0.0442919