631 research outputs found

    Light-Quark Vector Meson Spectroscopy

    Get PDF
    The current situation for vector meson spectroscopy is outlined, and it is shown that the data are inconsistent with the generally-accepted model for meson decay. A possible resolution in terms of exotic mesons is given. Although this resolves some of the issues, fresh theoretical questions are raised.Comment: Plenary talk at HADRON2001, Protvin

    Systematic Regge theory analysis of omega photoproduction

    Get PDF
    Systematic analysis of available data for ω\omega-meson photoproduction is given in frame of Regge theory. At photon energies above 20 GeV the γ+pω+p\gamma{+}p{\to}\omega{+}p reaction is entirely dominated by Pomeron exchange. However, it was found that Pomeron exchange model can not reproduce the γ+pρ+p\gamma{+}p{\to}\rho{+}p and γ+pω+p\gamma{+}p{\to}\omega{+}p data at high energies simultaneously with the same set of parameters. The comparison between ρ\rho and ω\omega data indicates a large room for meson exchange contribution to ω\omega-meson photoproduction at low energies. It was found that at low energies the dominant contribution comes from π\pi and f2f_2-meson exchanges. There is smooth transition between the meson exchange model at low energies and Regge theory at high energies.Comment: 7 pages, 8 figures, revtex

    Gamma(*)Gamma(*) reaction at high energies

    Full text link
    The energy available for gamma(*)gamma(*) physics at LEP2 is opening a new window on the study of diffractive phenomena, both non-perturbative and perturbative. We discuss some of the uncertainties and problems connected with the experimental measurements and their interpretation.Comment: 6 pages, 6 figures, submitted to proceedings of the Durham Collider Workshop, 22-26 September 199

    Impact of saturation on spin effects in proton-proton scattering

    Full text link
    For pomerons described by a sum of two simple-pole terms, a soft and a hard pomeron, the unitarity bounds from saturation in impact-parameter space are examined. We consider the effect of these bounds on observables linked with polarisation, such as the analyzing power in elastic proton-proton scattering, for LHC energies. We obtain the s and t dependence of the Coulomb-nuclear interference at small momentum transfer, and show that the effect of the hard pomeron may be observed at the LHC.Comment: 8 pages, 2 figures, presented by O.V.S. at the Advanced Studies Institute "Symetries and Spin" (SPIN-Praha-2004), Prague, July 5 - July 10, 200

    Spin Asymmetries In Diffractive J/ΨJ/\Psi Leptoproduction

    Full text link
    In this report we calculate the cross section and AllA_{ll} asymmetry for the diffractive J/ΨJ/\Psi leptoproduction. We study dependences of the asymmetry on the structure of the Pomeron-proton couplingComment: 4 pages, latex, two PS figures, presented at the International Workshop "Symmetry and Spin" PRAHA'9

    Photon-Photon and Pomeron-Pomeron Processes in Peripheral Heavy Ion Collisions

    Get PDF
    We estimate the cross sections for the production of resonances, pion pairs and a central cluster of hadrons in peripheral heavy-ion collisions through two-photon and double-pomeron exchange, at energies that will be available at RHIC and LHC. The effect of the impact parameter in the diffractive reactions is introduced, and imposing the condition for realistic peripheral collisions we verify that in the case of very heavy ions the pomeron-pomeron contribution is indeed smaller than the electromagnetic one. However, they give a non-negligible background in the collision of light ions. This diffractive background will be more important at RHIC than at LHC.Comment: 22 pages, 1 Postscript figures, 4 tables, to appear in Phys. Rev.

    Hunting the Vector Hybrid

    Get PDF
    The current state of analysis of e+e- annihilation below 2.0 GeV and of the vector component of tau decay is reviewed. The evidence for and against the presence of hybrid vectors is discussed. It is concluded that the data strongly favour their inclusion, and the consequences of this are outlined.Comment: 21 pages, 4 figures Minor typos corrected. Some changes on p.

    Simulation of UHE muons propagation for GEANT3

    Get PDF
    A simulation package for the transport of high energy muons has been developed. It has been conceived to replace the muon propagation software modules implemented in the detector simulation program GEANT3. Here we discuss the results achieved with our package and we check the agreement with numerical calculations up to 10**8 GeV.Comment: 21 pages, 6 figures, 1 Table. AMSTeX document, acknowledgments adde

    Production of eta Mesons in Double Pomeron Exchange

    Full text link
    We estimate the production cross sections for ηc\eta_c and ηb\eta_b mesons via pomeron-pomeron fusion in peripheral heavy-ion collisions. Total and elastic PP cross sections are calculated in an equivalent pomeron approximation.Comment: 9 pages, 3 Postscript figure

    Comment on "Regge Trajectories for All Flavors"

    Get PDF
    We show that Regge trajectories for all flavors suggested recently by Filipponi et al. cannot combine both meson spectroscopy and additivity of intercepts. Other defects of these trajectories are also discussed.Comment: 2 pages, LaTe
    corecore