790 research outputs found

    J/psi c\bar{c} production in e+e- and hadronic interactions

    Full text link
    Predictions of the nonperturbative Quark Gluon Strings model based on the 1/N-expansion in QCD and string picture of interactions for production of states containing heavy quarks are considered. Relations between fragmentation functions for different states are used to predict the fragmentation function of c-quark to J/psi-mesons. The resulting cross section for J/psi-production in e+e- annihilation is in a good agreement with recent Belle result. It is argued that associated production of c\bar{c} states with open charm should give a substantial contribution to production of these states in hadronic interactions at very high energies.Comment: 7 pages, 2 figure

    Diffractive Dissociation in Deep Inelastic Scattering at HERA

    Get PDF
    The diffraction dissociation of virtual photons is considered in the framework of conventional Regge theory. It is shown that the recent HERA data on large rapidity gap events can be successfully described in terms of the Pomeron structure function. Using Regge factorization, the latter can be related to the deuteron structure function. The parameters which relate these two structure functions are determined from soft hadronic diffraction data. The size of the shadowing corrections at low x and large Q**2 is also obtained.Comment: 17 pages, TEX, preprint LPTHE Orsay 94-4

    Elliptic Flow and Fixed p_T Suppression in a Final State Interaction Model

    Full text link
    It has been shown that a final state interaction model, used to describe J/psi suppression, can also describe the fixed p_T suppression of the pi^0 (and charged pions) yield at all values of p_T, with a final state interaction cross-section sigma close to one milibarn. We propose an extension of the model to the pion motion in the transverse plane - which introduces a dependence of the suppression on the azimuthal angle theta_R. Using the same value of sigma, we obtain values of the elliptic flow v_2 close to the experimental ones, for all values of p_T, including the soft p_T region.Comment: 21 pages, 6 figure

    Description of soft diffraction in the framework of reggeon calculus. Predictions for LHC

    Get PDF
    A model, based on Gribov's Reggeon calculus, is proposed and applied to processes of soft diffraction at high energies. It is shown that by accounting for absorptive corrections for all legs of triple-Regge and loop diagrams a good description of experimental data on inelastic soft diffraction can be obtained. In this paper we give a brief description of the model and of its predictions for LHC energies.Comment: Talk given at EDS'09 conferenc

    On the Behavior of F2 and its Logarithmic Slopes

    Get PDF
    It is shown that the CKMT model for the nucleon structure function F2, taken as the initial condition for the NLO evolution equations in perturbative QCD, provides a good description of the HERA data when presented in the form of the logarithmic slopes of F2 vs x and Q2 (Caldwell-plot), in the whole available kinematic ranges. Also the results obtained for the behavior of the gluon component of a nucleon are presented.Comment: 16 pages, 10 figure
    • …