Large pT Hadroproduction of Heavy Quarks and Quarkonia

The production of heavy quarks at large Pt (Pt >> m) in hadronic collisions is considered in the framework of perturbative fragmentation functions, allowing a resummation at the NLO level of final state large mass logarithms of the kind log (Pt/m). The resulting theoretical uncertainty from factorization/renormalizationscales at large Pt is shown to be much smaller than that shown by the full 0 (\α3) perturbative calculation. Then the production of heavy quarkonia at large tranverse momenta is discussed by including the mechanism of fragmentation, in particular the direct fragmentation to J/\ψ and the fragmentation to \χ states followed by radiative decay to J/\ψ. The overall theoretical estimate is shown to be nearly consistent with the experimental observation for J/\ψ. On the contrary the situation is quite unsatisfactory for the \ψ', demanding for a new mechanism dominating the production process.