27,930 research outputs found

    Charmonium-Nucleon Dissociation Cross Sections in the Quark Model

    Full text link
    Charmonium dissociation cross sections due to flavor-exchange charmonium-baryon scattering are computed in the constituent quark model. We present results for inelastic J/ψNJ/\psi N and ηcN\eta_c N scattering amplitudes and cross sections into 46 final channels, including final states composed of various combinations of DD, D∗D^*, Σc\Sigma_c, and Λc\Lambda_c. These results are relevant to experimental searches for the deconfined phase of quark matter, and may be useful in identifying the contribution of initial ccˉc\bar c production to the open-charm final states observed at RHIC through the characteristic flavor ratios of certain channels. These results are also of interest to possible charmonium-nucleon bound states.Comment: 10 pages, 5 eps figures, revte

    Molecular beam epitaxial growth of high-quality InSb on InP and GaAs substrates

    Get PDF
    Epitaxial layers of InSb were grown on InP and GaAs substrates by molecular beam epitaxy. The dependence of the epilayer quality on flux ratio, J sub Sb4/J sub In, was studied. Deviation from an optimum value of J sub Sb4/J sub In (approx. 2) during growth led to deterioration in the surface morphology and the electrical and crystalline qualities of the films. Room temperature electron mobilities as high as 70,000 and 53,000 sq cm /V-s were measured in InSb layers grown on InP and GaAs substrates, respectively. Unlike the previous results, the conductivity in these films is n-type even at T = 13 K, and no degradation of the electron mobility due to the high density of dislocations was observed. The measured electron mobilities (and carrier concentrations) at 77 K in InSb layers grown on InP and GaAs substrates are 110,000 sq cm/V-s (3 x 10(15) cm(-3)) and 55,000 sq cm/V-s (4.95 x 10(15) cm(-3)), respectively, suggesting their application to electronic devices at cryogenic temperatures

    Identification of Vibration-Induced Noise Radiated from Compressor Shell

    Get PDF

    Performance of a prototype active veto system using liquid scintillator for a dark matter search experiment

    Full text link
    We report the performance of an active veto system using a liquid scintillator with NaI(Tl) crystals for use in a dark matter search experiment. When a NaI(Tl) crystal is immersed in the prototype detector, the detector tags 48% of the internal K-40 background in the 0-10 keV energy region. We also determined the tagging efficiency for events at 6-20 keV as 26.5 +/- 1.7% of the total events, which corresponds to 0.76 +/- 0.04 events/keV/kg/day. According to a simulation, approximately 60% of the background events from U, Th, and K radioisotopes in photomultiplier tubes are tagged at energies of 0-10 keV. Full shielding with a 40-cm-thick liquid scintillator can increase the tagging efficiency for both the internal K-40 and external background to approximately 80%.Comment: Submitted to Nuclear Instruments and Methods in Physics Research Section

    Higher Derivative CP(N) Model and Quantization of the Induced Chern-Simons Term

    Get PDF
    We consider higher derivative CP(N) model in 2+1 dimensions with the Wess-Zumino-Witten term and the topological current density squared term. We quantize the theory by using the auxiliary gauge field formulation in the path integral method and prove that the extended model remains renormalizable in the large N limit. We find that the Maxwell-Chern-Simons theory is dynamically induced in the large N effective action at a nontrivial UV fixed point. The quantization of the Chern-Simons term is also discussed.Comment: 8 pages, no figure, a minor change in abstract, added Comments on the quantization of the Chern-Simons term whose coefficient is also corrected, and some references are added. Some typos are corrected. Added a new paragraph checking the equivalence between (3) and (5), and a related referenc

    Energy levels of the soliton--heavy-meson bound states

    Get PDF
    We investigate the bound states of heavy mesons with finite masses to a classical soliton solution in the Skyrme model. For a given model Lagrangian we solve the equations of motion exactly so that the heavy vector mesons are treated on the same footing as the heavy pseudoscalar mesons. All the energy levels of higher grand spin states as well as the ground state are given over a wide range of the heavy meson masses. We also examine the validity of the approximations used in the literatures. The recoil effect of finite mass soliton is naively estimated.Comment: 24 pages, REVTeX v3.0, 6 figures are available upon request

    Deformations of coisotropic submanifolds for fibrewise entire Poisson structures

    Get PDF
    We show that deformations of a coisotropic submanifold inside a fibrewise entire Poisson manifold are controlled by the L∞L_\infty-algebra introduced by Oh-Park (for symplectic manifolds) and Cattaneo-Felder. In the symplectic case, we recover results previously obtained by Oh-Park. Moreover we consider the extended deformation problem and prove its obstructedness

    Synchronization transition of heterogeneously coupled oscillators on scale-free networks

    Full text link
    We investigate the synchronization transition of the modified Kuramoto model where the oscillators form a scale-free network with degree exponent λ\lambda. An oscillator of degree kik_i is coupled to its neighboring oscillators with asymmetric and degree-dependent coupling in the form of \couplingcoeff k_i^{\eta-1}. By invoking the mean-field approach, we determine the synchronization transition point JcJ_c, which is zero (finite) when η>λ−2\eta > \lambda-2 (η<λ−2\eta < \lambda-2). We find eight different synchronization transition behaviors depending on the values of η\eta and λ\lambda, and derive the critical exponents associated with the order parameter and the finite-size scaling in each case. The synchronization transition is also studied from the perspective of cluster formation of synchronized vertices. The cluster-size distribution and the largest cluster size as a function of the system size are derived for each case using the generating function technique. Our analytic results are confirmed by numerical simulations.Comment: 11 pages, 3 figures and two table

    Electroweak phase transition in a nonminimal supersymmetric model

    Full text link
    The Higgs potential of the minimal nonminimal supersymmetric standard model (MNMSSM) is investigated within the context of electroweak phase transition. We investigate the allowed parameter space yielding correct electroweak phase transitoin employing a high temperature approximation. We devote to phenomenological consequences for the Higgs sector of the MNMSSM for electron-positron colliders. It is observed that a future e+e−e^+ e^- linear collider with s=1000\sqrt{s} = 1000 GeV will be able to test the model with regard to electroweak baryogenesis.Comment: 28 pages, 5 tables, 12 figure

    Baryons with Two Heavy Quarks as Solitons

    Get PDF
    Using the chiral soliton model and heavy quark symmetry we study baryons containing two heavy quarks. If there exists a stable (under strong interactions) meson consisting of two heavy quarks and two light ones, then we find that there always exists a state of this meson bound to a chiral soliton and to a chiral anti-soliton, corresponding to a two heavy quark baryon and a baryon containing two heavy anti-quarks and five light quarks, or a ``heptaquark".Comment: 7 pages and 2 postscript figures appended, LaTex, UCI-TR 94-3
    • …
    corecore