1,118 research outputs found

    Exclusive ϕ\phi production in proton-proton collisions in the resonance model

    Full text link
    The exclusive ϕ\phi meson production in proton-proton reactions is calculated within the resonance model. The considered model was already successfully applied to the description of π\pi, η\eta, ρ\rho, ω\omega, ππ\pi\pi production in proton-proton collisions. The only new parameter entering into the model is the ωϕ\omega-\phi mixing angle θmix\theta_{mix} which is taken equal to θmix3.7o\theta_{mix} \approx 3.7^o.Comment: 7 pages, 1 figure, to appear in the brief report section of PR

    Is the anomalous decay ratio of D_{sJ}(2632) due to isospin breaking?

    Full text link
    Quark pair annihilation into gluons is suppressed at large momenta due to the asymptotic freedom. As a consequence, mass eigenvalues of heavy states should be almost diagonal with respect to up and down quark masses, thereby breaking isospin. We suggest the particle observed by the SELEX Collaboration, D_{sJ}(2632) to be to a good extent a [cd][dbar sbar] state, which would explain why its D^0 K^+ mode is anomalously suppressed with respect to D_s eta. Predictions for the rates of the yet unobserved modes D_s pi^0 and D^+ K^0 are given.Comment: 3 pages, 1 figur

    Empirical Determination of Threshold Partial Wave Amplitudes in ppppωp p \to p p \omega

    Full text link
    Using the model independent irreducible tensor approach to ω\omega production in pppp collisions, we show theoretically that, it is advantageous to measure experimentally the polarization of ω\omega, in addition to the proposed experimental study employing a polarized beam and a polarized target.Comment: 6 pages, 1 Table, Latex-2

    Glueball enhancements in p(gamma,VV)p through vector meson dominance

    Full text link
    Double vector meson photoproduction, p(gamma, G -> VV)p, mediated by a scalar glueball G is investigated. Using vector meson dominance (VMD) and Regge/pomeron phenomenology, a measureable glueball enhancement is predicted in the invariant VV = rho rho and omega omega mass spectra. The scalar glueball is assumed to be the lightest physical state on the daughter pomeron trajectory governing diffractive vector meson photoproduction. In addition to cross sections, calculations for hadronic and electromagnetic glueball decays, G -> V V' (V,V'= rho, omega, phi, gamma), and gamma_v V -> G transition form factors are presented based upon flavor universality, VMD and phenomenological couplings from phi photoproduction analyses. The predicted glueball decay widths are similar to an independent theoretical study. A novel signature for glueball detection is also discussed

    Polarization Observables in γNKKˉN\gamma N\to K\bar{K}N

    Full text link
    We explore some of the rich structure of the polarization observables recently developed for processes like γNππN\gamma N\to\pi\pi N and γNKKˉN\gamma N\to K \bar{K} N in the framework of a specific model for the latter process. Emphasis is placed on observables that may be accesible at existing facilities in the near future. The sensitivity of the observables to the details of the model indicate that they will be a very useful tool in differentiating between different models for reactions like these. In the framework of a model for γNKKˉN\gamma N\to K \bar{K} N, we examine the sensitivity of the observables to coupling constants of the ϕ\phi, to the properties of the Λ(1405)\Lambda(1405), and to the existence of the Θ+\Theta^+.Comment: 21 pages, latex, 17 figures, 1 style file include

    GEOCHEMISTRY, ZIRCON U-PB GEOCHRONOLOGY, ND-HF ISOTOPIC CHARACTERISTICS AND TECTONIC IMPLICATIONS OF THE SOUTH MUYA BLOCK METASEDIMENTS (NORTHEASTERN CENTRAL ASIAN OROGENIC BELT)

    Get PDF
    The Neoproterozoic to Cenozoic collage of the Central Asian Orogenic Belt is well-known to include Precambrian continental blocks and microcontinents traditionally attributed to rifting of Siberia or Gondwana prior to CAOB assembly that significantly contributed into the geochemical and isotopic composition of younger subduction- and accretion-related crustal lithologies via processes of crust-mantle interaction and crustal recycling.The Neoproterozoic to Cenozoic collage of the Central Asian Orogenic Belt is well-known to include Precambrian continental blocks and microcontinents traditionally attributed to rifting of Siberia or Gondwana prior to CAOB assembly that significantly contributed into the geochemical and isotopic composition of younger subduction- and accretion-related crustal lithologies via processes of crust-mantle interaction and crustal recycling

    Diquark-Antidiquarks with Hidden or Open Charm and the Nature of X(3872)

    Full text link
    Heavy-light diquarks can be the building blocks of a rich spectrum of states which can accommodate some of the newly observed charmonium-like resonances not fitting a pure c-cbar assignment. We examine this possibility for hidden and open charm diquark-antidiquark states deducing spectra from constituent quark masses and spin-spin interactions. Taking the X(3872) as input we predict the existence of a 2++ state that can be associated to the X(3940) observed by Belle and re-examine the state claimed by SELEX, X(2632). The possible assignment of the previously discovered states D_s(2317) and D_s(2457) is discussed. We predict X(3872) to be made of two components with a mass difference related to (m_u-m_d) and discuss the production of X(3872) and of its charged partner X^(+-) in the weak decays of B^(+,0).Comment: 11 pages, 2 figures, revtex, minor typos correcte

    Fast Scramblers Of Small Size

    Full text link
    We investigate various geometrical aspects of the notion of `optical depth' in the thermal atmosphere of black hole horizons. Optical depth has been proposed as a measure of fast-crambling times in such black hole systems, and the associated optical metric suggests that classical chaos plays a leading role in the actual scrambling mechanism. We study the behavior of the optical depth with the size of the system and find that AdS/CFT phase transitions with topology change occur naturally as the scrambler becomes smaller than its thermal length. In the context of detailed AdS/CFT models based on D-branes, T-duality implies that small scramblers are described in terms of matrix quantum mechanics.Comment: 14 pages, 3 figures. Added reference

    (Field) Symmetrization Selection Rules

    Full text link
    QCD and QED exhibit an infinite set of three-point Green's functions that contain only OZI rule violating contributions, and (for QCD) are subleading in the large N_c expansion. The Green's functions describe the ``decay'' of a J^{PC}={1,3,5 ...}^{-+} exotic hybrid meson current to two J=0 (hybrid) meson currents with identical P and C. We prove that the QCD amplitude for a neutral hybrid {1,3,5 ...}^{-+} exotic current to create eta pi0 only comes from OZI rule violating contributions under certain conditions, and is subleading in N_c.Comment: 20 pages, LaTeX. Two postscript figures. Final published versio

    Omega Production in pp Collisions

    Full text link
    A model-independent irreducible tensor formalism which has been developed earlier to analyze measurements of ppppπ\vec{p}\vec{p}\to pp \pi^\circ, is extended to present a theoretical discussion of ppppω\vec{p}\vec{p}\to pp \omega and the polarization of ω\omega in ppppωpp\to pp \vec{\omega}. The recent measurement of unpolarized differential cross section for ppppωpp\to pp \omega is analyzed using this theoretical formalism.Comment: 5 pages (double column), no figures, uses revtex
    corecore