7,787 research outputs found

    Gluon fragmentation to ^3D_J quarkonia

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    We present a calculation of the leading order QCD fragmentation functions for gluons to split into spin-triplet D-wave quarkonia. We apply them to evaluate the gluon fragmentation contributions to inclusive ^3D_J quarkonium production at large transverse momentum processes like the Tevatron and find that the D-wave quarkonia, especially the charmonium 2^{--} state, could be observed through color-octet mechanism with present luminosity. Since there are distinctively large gaps between the contributions of two different (i.e, color-singlet and color-octet) quarkonium production mechanisms, our results may stand as a unique test to NRQCD color-octet quarkonium production mechanism.Comment: 15 pages in LaTex (2 figures in PS-file

    D-wave heavy quarkonium production in fixed target experiments

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    We calculate the DD-wave heavy quarkonium production at fixed target experiments under the NRQCD factorization formalism. We find that the color octet contributions are two orders of magnitude larger than color-singlet contributions if color-octet matrix elements are taken according to the NRQCD velocity scaling rules. Within the theoretical uncertainties, the prediction for the production rate of 22^{--} DD-wave charmonium state agrees with the preliminary result of E705 and other experiments. Searching for the 11^{--} DD-wave state ψ(3770)\psi(3770) is further suggested.Comment: 13pages, 4 PS figures, final vertion to appear in PR

    Spectrum of Curvature Perturbation of Multi-field Inflation with Small-Field Potential

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    In this paper, we have studied the spectrum of curvature perturbation of multi-field inflation with general small-field potential. We assume that the isocurvature perturbation may be neglected, and by using the Sasaki-Stewart formalism, we found that the spectrum may be redder or bluer than of its corresponding single field. The result depends upon the values of fields and their effective masses at the horizon-crossing time. We discuss the relevant cases.Comment: 8 pages, no figure, to publish in JCA

    A Crucial Test for Color-Octet Production Mechanism in Z^0 Decays

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    The direct production rates of DD-wave charmonia in the decays of Z0Z^0 is evaluated. The color-octet production processes Z03DJ(ccˉ)qqˉZ^0\rightarrow ^3D_J(c\bar c) q\bar q are shown to have distinctively large branching ratios, the same order of magnitude as that of J/ψJ/\psi prodution, as compared with other DD-wave charmonium production mechanisms. This may suggest a crucial channel to test the color-octet mechanism as well as to observe the DD-wave charmonium states in Z0Z^0 decays. In addition, a signal for the 3DJ^3D_J charmonium as strong as J/ψJ/\psi or ψ\psi^\prime with large transverse momentum at the Tevatron should also be observed.Comment: 14 pages in LaTex (3 figures in PS-file

    Large Possible retardation effects of quark confinement on the meson spectrum II

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    We present the results of a study of heavy-light-quark bound states in the context of the reduced Bethe-Salpeter equation with relativistic vector and scalar interactions. We find that satisfactory fits may also be obtained when the retarded effect of the quark-antiquark interaction is concerned.Comment: 11 pages, RevTex, to appear in PR

    Possible retardation effects of quark confinement on the meson spectrum

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    The reduced Bethe-Salpeter equation with scalar confinement and vector gluon exchange is applied to quark-antiquark bound states. The so called intrinsic flaw of Salpeter equation with static scalar confinement is investigated. The notorious problem of narrow level spacings is found to be remedied by taking into consideration the retardation effect of scalar confinement. Good fit for the mass spectrum of both heavy and light quarkomium states is then obtained.Comment: 14 pages in LaTex for

    The Parametric Symmetry and Numbers of the Entangled Class of 2 \times M \times N System

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    We present in the work two intriguing results in the entanglement classification of pure and true tripartite entangled state of 2×M×N2\times M\times N under stochastic local operation and classical communication. (i) the internal symmetric properties of the nonlocal parameters in the continuous entangled class; (ii) the analytic expression for the total numbers of the true and pure entangled class 2×M×N2\times M \times N states. These properties help people to know more of the nature of the 2×M×N2\times M\times N entangled system.Comment: 12 pages, 5 figure
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