CLAS physics database search results Measurement E159M668 E1-6 V. Burkert 2001 psi(p) dsigma/dpsi_pr Data errors deg mcb/rad mcb/rad 30 0.105718 0.0245888 90 0.11295 0.0244418 150 0.0904782 0.0235385 210 0.107077 0.0283883 270 0.0854117 0.0175204 330 0.0918559 0.0224931