29,669 research outputs found

    ξ(2230)\xi(2230) is likely to be a glueball

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    On the basis of the recent results of ξ(2230)→π+π−,ppˉ\xi(2230)\rightarrow \pi^+\pi^-, p\bar p and ξ(2230)→K+K−, KSKS\xi(2230)\rightarrow K^+K^-,~K_SK_S, measured by the BES Collaboration in J/ψJ/\psi radiative decays, combined with the PS185 experiment of ppˉ→ξ(2230)→KKˉp\bar p\rightarrow \xi(2230)\rightarrow K\bar K, we argue that because of its very narrow partial decay widths to ππ\pi\pi and KKˉK\bar K ( less than 1 MeV1~MeV ), its large production rate in J/ψJ/\psi radiative decays, and its flavor- symmetric couplings to ππ\pi\pi and KKˉK\bar K, the ξ(2230)\xi(2230) is very likely to be a JPC=(even)++J^{PC}=(even)^{++} glueball.Comment: 6 pages in Latex, talk presented at the CCAST Workshop on Tau-Charm Factory, Beijing, November 199

    Search for C=+C=+ charmonium and bottomonium states in e+e−→γ+Xe^+e^-\to \gamma+ X at B factories

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    We study the production of C=+C=+ charmonium states XX in e+e−→γ+Xe^+e^-\to \gamma + X at B factories with X=ηc(nS)X=\eta_c(nS) (n=1,2,3), χcJ(mP)\chi_{cJ}(mP) (m=1,2), and 1D2(1D)^1D_2(1D). In the S and P wave case, contributions of tree-QED with one-loop QCD corrections are calculated within the framework of nonrelativistic QCD(NRQCD) and in the D-wave case only the tree-QED contribution are considered. We find that in most cases the QCD corrections are negative and moderate, in contrast to the case of double charmonium production e+e−→J/ψ+Xe^+e^-\to J/\psi + X, where QCD corrections are positive and large in most cases. We also find that the production cross sections of some of these states in e+e−→γ+Xe^+e^-\to \gamma + X are larger than that in e+e−→J/ψ+Xe^+e^-\to J/\psi + X by an order of magnitude even after the negative QCD corrections are included. So we argue that search for the X(3872), X(3940), Y(3940), and X(4160) in e+e−→γ+Xe^+e^-\to \gamma + X at B factories may be helpful to clarify the nature of these states. For completeness, the production of bottomonium states in e+e−e^+e^- annihilation is also discussed.Comment: 13pages, 4 figure

    The Color-Octet intrinsic charm in η′\eta^\prime and B→η′XB\to \eta^\prime X decays

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    Color-octet mechanism for the decay B\to \eta^\prime X is proposed to explain the large branching ratio of Br(B\to \eta^\prime X)\sim 1\times 10^{-3} recently announced by CLEO. We argue that the inclusive \eta^\prime production in B decays may dominantly come from the Cabbibo favored b\to (\bar c c)_8s process where \bar c c pair is in a color-octet configuration, and followed by the nonperturbative transition (\bar c c)_8\to \eta^\prime X. The color-octet intrinsic charm component in the higher Fock states of \eta^\prime is crucial and is induced by the strong coupling of \eta^\prime to gluons via QCD axial anomaly.Comment: 9 pages, RevTex, 1 PS figur

    Transmitted sound field due to an impulsive line acoustic source bounded by a plate followed by a vortex sheet

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    The propagation of sound due to a line acoustic source in the moving stream across a semiinfinite vortex sheet which trails from a rigid plate is examined in a linear theory for the subsonic case. A solution for the transmitted sound field is obtained with the aid of multiple integral transforms and the Wiener-Hopf technique for both the steady state (time harmonic) and initial value (impulsive source) situations. The contour of inverse transform and hence the decomposition of the functions are determined through causality and radiation conditions. The solution obtained satisfies causality and the full Kutta conditions. The transmitted sound field is composed of two waves in both the stady state and initial value problems. One is the wave scattered from the edge of the plate which is associated with the bow wave and the instability wave. These waves exist in the downstream sectors. The other is the wave transmitted through the vortex sheet which is also associated with the instability wave. Regional divisions of the transmitted sound field are identified

    Reply to Comment on "Chiral suppression of scalar glueball decay"

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    Reply to the comment of Chao, He, and Ma

    Multiquark Hadrons

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    A number of candidate multiquark hadrons, i.e., particle resonances with substructures that are more complex than the quark-antiquark mesons and three-quark baryons that are prescribed in the textbooks, have recently been observed. In this talk I present: some recent preliminary BESIII results on the near-threshold behavior of sigma(e+e- --> Lambda Lambda-bar) that may or may not be related to multiquark mesons in the light- and strange-quark sectors; results from Belle and LHCb on the electrically charged, charmoniumlike Z(4430)^+ --> pi^+ psi ' resonance that necessarily has a four-quark substructure; and the recent LHCb discovery of the P_c(4380) and P_c(4450) hidden-charm resonances seen as a complex structure in the J/psi p invariant mass distribution for Lambda_b --> K^-J/psi p decays and necessarily have a five-quark substructure and are, therefore, prominent candidates for pentaquark baryons.Comment: 12 pages, 9 figures, summary of a talk presented at the 12th Conference on Hypernuclear and Strange Particle Physics (HYP2015), September 7-12, 2015 Sendai, JAPAN. To appear in the JPS Conference proceeding

    New high fill-factor triangular micro-lens array fabrication method using UV proximity printing

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    A simple and effective method to fabricate a high fill-factor triangular microlens array using the proximity printing in lithography process is reported. The technology utilizes the UV proximity printing by controlling a printing gap between the mask and substrate. The designed approximate triangle microlens array pattern can be fabricated the high fill-factor triangular microlens array in photoresist. It is due to the UV light diffraction to deflect away from the aperture edges and produce a certain exposure in photoresist material outside the aperture edges. This method can precisely control the geometric profile of high fill factor triangular microlens array. The experimental results showed that the triangular micro-lens array in photoresist could be formed automatically when the printing gap ranged from 240 micrometers to 840 micrometers. The gapless triangular microlens array will be used to increases of luminance for backlight module of liquid crystal displays.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

    Epigenetic silencing of SOCS3 expression contributes to fibrosis in Crohn’s disease

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    Identified risk polymorphisms affecting the Jak-STAT3 pathway in patients with Crohn’s disease could affect TGF-β1 and collagen I expression and in the pathway’s negative regulator, SOCS3. Genetic factors, however, account for only ~25% of disease. Epigenetic events also shape gene expression. Recent experiments showed that autocrine IL-6 production in mesenchymal cells, subepithelial myofibroblasts (SEMF) and muscle cells, of patients with fibrostenotic Crohn’s disease causes sustained Jak-STAT3 activity, excess TGF-β1 and Collagen I production and fibrosis. SOCS3 paradoxically decreased in these cells. We now identify epigenetic mechanisms that silence SOCS3 expression in SEMF of patients with fibrostenotic Crohn’s disease. In a previous experiment, using isolated SEMF of normal ileum and affected ileum from patients with each Crohn’s phenotype, inflammatory (Montreal B1), fibrostenotic (B2) and penetrating (B3), we confirmed decreased SOCS3 protein levels were unique to B2 patients. Expression of miR-19b increased in SEMF of affected ileum. SOCS3 transcriptional activity decreased after transfection of miR-19b mimic and increased when antagomiR-19b was expressed. Epigenetic silencing of SOCS3 in ileal SEMF of patients with fibrostenotic Crohn’s disease occurs by increased miR-19b mediated inhibition of SOCS3

    Cancellation of Infrared Divergences in Hadronic Annihilation Decays of Heavy Quarkonia

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    In the framework of a newly developed factorization formalism which is based on NRQCD, explicit cancellations are shown for the infrared divergences that appeared in the previously calculated hadronic annihilation decay rates of P-wave and D-wave heavy quarkonia. We extend them to a more general case that to leading order in v2v^2 and next-to-leading order in αs\alpha_s, the infrared divergences in the annihilation amplitudes of color-singlet QQˉ(2S+1LJ)Q\bar{Q}(^{2S+1}L_J) pair can be removed by including the contributions of color-octet operators QQˉ(2S+1(L−1)J′)Q\bar{Q}(^{2S+1}(L-1)_{J'}), QQˉ(2S+1(L−3)J′′)Q\bar{Q}(^{2S+1}(L-3)_{J''}), ... in NRQCD. We also give the decay widths of 3DJ→LH^3D_J\rightarrow LH at leading order in αs\alpha_s.Comment: 8 pages, LaTex(3 figures included), to be publishe
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