F. Abe et al., PRODUCTION OF J PSI MESONS FROM CHI(C) MESON DECAYS IN P(P)OVER-BAR COLLISIONS AT ROOT-S=1.8 TEV/, Physical review letters, 79(4), 1997, pp. 578-583
We have measured the fraction of J/psi mesons originating from chi(c)
meson decays in p (p) over bar collisions at root s = 1.8 TeV. The fra
ction, for P-T/(J/psi) > 4.0 GeV/c and \(eta) over dot(J/psi) < 0.6, n
ot including contributions from b flavored hadrons, is 29.7% +/- 1.7%(
stat) +/- 5.7%(syst). We have determined the cross sections for J/psi
mesons originating from chi(c) decays and for directly produced J/psi
mesons. We have found that direct J/psi production is in excess of the
prediction of the color singlet model by the same factor found for di
rect psi(2S) production.