Diquark Fragmentation In E～+e～-→c(?)q(?)→h's Process And Associate Strange Particle Enhancement In Υ→J/Ψ+X

In e~+e~- annihilation at High Energies, many partons (gluons and quarks) are produced at the end of parton shower process described by Perturbative Quantum Chromo-dynamics (PQCD). In principle, the colour connection between these partons should be determined by PQCD. Unfortunately, PQCD can not choose a definite one among so many kinds of colour connection. Different colour connection will lead to different hadronization effect, and produce different final hadron state. Hence, it is instructive to study the special properties of the final hadrons, which could give information for the evidence of specific colour connection. Phenomenological study on the colour connection can provide some clues for Nonperturbative Quantum Chromodynamics (NPQCD), the central idea of such investigation can be to explore the direct and solid relations between a certain kind of colour connection on the parton system and the observations of final state hadron system. The predictions on these observations are compared with data, and one can extract how nature choose among all the colour connections. For this aim, heavy quark plays an important role. Their large masses naturally set the hard scale, so that the heavy quarks production via strong interaction can be calculated by PQCD, while the structure of heavy hadrons are ruled by NPQCD. Hence one can expect a direct correspondence between the heavy quark and heavy hadron.For the e~+e~- → ccqq → h's process, we investigate a certain colour connection that cq and cq are in 3~* and 3, respectively. There are no models that can be applied to describe the hadronization process with respect to such kind of colour connection in a general case. However, for a special case when cq and cq are both near the threshold of diquark and antidiquark masses, we propose a toy model, i.e. via diquark fragmentation to describe their hadronization effects. We predict the momentatum spectra of ∧_c for the cases both in colour connection (3(?)3)(?)(3~*(?)3~*)→ 3~* (?)3 and the ordinary one (3 (?)3~*)(?)(3(?)3~*) → 1 (?) 1, our results show that the momentum spectra via diquark fragmentation are harder than those via ordinary colour connection. Compared with data, one can find that the results obtained by PYTHIA are all somehow softer than the data. So we conclude that the data supports the existence of the colour connection form (3 (?) 3) (?) (3~* (?) 3~*) → 3~* (?) 3. Moreover, we point out that the correlations between the charm baryons and charm antibaryons are much stronger in diquark fragmentation, which is another signal for the colour connection.For the inclusive process Υ → J/Ψ + X, it is found that the colour singlet process Υ → J/Ψ + ccg can explain the data not only in momentum spectra but also in branching ratio. Its special character is the associate charm production. To investigate the possibility of measuring the associate ccg, it is natural to investigate charm dom-inantly decays into strange, so we calculate the relative production of accompanying produced strange particles in Υ decay. From the ratios of < K > / < π >, We find that only the ccg cluster in colour signal will lead to significant strange particle enhancement, it must be a single to probe the colour singlet process Υ → J/Ψ + X.