Intrinsic quarks and heavy flavour production

Abstract

A model is constructed for the diffractive production of heavy flavours in hadron-hadron interactions, based on the presence of an intrinsic heavy quark component in the hadron wavefunction. It requires three ingredients; the heavy quark content of the initial hadron, the probability that these heavy quarks are scattered, and the probability that they form heavy flavoured hadrons afterwards. The initial heavy quark distributions are calculated, using lowest order perturbative QCD, starting from the valence constituent quark distributions, and compared with deep inelastic charm production data. The valence distributions are designed to reproduce the dimensional counting rules, and, via reciprocity, to be consistent with the heavy quark fragmentation functions. The light quark-hadron scattering cross-section is parametrized by Pomeron exchange, and extended to heavy quarks using the f-dominance hypothesis for the Pomeron- quark coupling. Dynamical and kinematical factors which control the rise of these cross-sections from threshold are built in. The validity of these ideas is tested against charm photo-production data, by using a vector dominance model for the photon-hadron scattering. The probability that the scattered quarks recombine to produce heavy flavoured hadrons is assumed to be given by the overlap of the initial distribution of quarks with the distribution in a heavy hadron. We compare the predictions of our model with strangeness and charm production data, and make predictions for bottom and top production. In particular, the magnitude of the leptonic signal to be expected from the decay of top quarks produced at the CERN pp-Collider is given. We conclude that all aspects of this model are consistent with present experimental data, and that the top quark should be observed at the Collider if its mass is around 35 GeV.