17,548 research outputs found

    The Y(3940), Z(3930) and the X(4160) as dynamically generated resonances from the vector-vector interaction

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    We study the vector-vector interaction within the framework of the hidden gauge formalism for the sector with quantum numbers charm C=0 and strangeness S=0 in the region around 4000 MeV. We get five poles, three of which could be identified with the Y(3940), Z(3930) and X(4160). These poles appear with quantum numbers I=0 and JPC=0++,2++J^{PC}=0^{++},2^{++} and 2++2^{++}, respectively, and can be considered as hadronic molecules made of D∗Dˉ∗D^*\bar{D}^*, Ds∗Dˉs∗D_s^*\bar{D}^*_s.Comment: to appear in Proceedings of XIII International Conference on Hadron Spectroscopy, November 29 - December 4, 2009, Florida State Universit

    Screening in three-dimensional QED with arbitrary fermion mass

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    We compute the quark--antiquark potential in three dimensional massive Quantum Electrodynamics for arbitrary fermion mass. The result indicates that screening prevails for any quark masses, contrary to the classical expectations, generalizing our previous result obtained for large masses. We also test the validity of several approximation schemes using a detailed numerical analysis. The classical result is still reproduced for small separation of the quarks.Comment: latex, 10 pages, 4 figures (6 ps-files

    Detailed atmospheric abundance analysis of the optical counterpart of the IR source IRAS 16559-2957

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    We have undertaken a detailed abundance analysis of the optical counterpart of the IR source IRAS16559-2957 with the aim of confirming its possible post-AGB nature. The star shows solar metallicity and our investigation of a large number of elements including CNO and 12C/13C suggests that this object has experienced the first dredge-up and it is likely still at RGB stage.Comment: 10 pages, 4 figures, 4 tables. To be published by Revista Mexicana de Astronomia y Astrofisica, April 201

    A venting alarm system for cryogenic liquids

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    Alarm system for cryogenic fluid storage tank

    Charm at FAIR

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    Charmed mesons in hot and dense matter are studied within a self-consistent coupled-channel approach for the experimental conditions of density and temperature expected at the CBM experiment at FAIR/GSI. The DD meson spectral function broadens with increasing density with an extended tail towards lower energies due to Λc(2593)N−1\Lambda_c(2593) N^{-1} and Σc(2800)N−1\Sigma_c(2800) N^{-1} excitations. The in-medium Dˉ\bar D meson mass increases with density. We also discuss the consequences for the renormalized properties in nuclear matter of the charm scalar Ds0(2317)D_{s0}(2317) and D(2400), and the predicted hidden charm X(3700) resonances at FAIR energies.Comment: 6 pages, 3 figures, to appear in the proceedings of ExcitedQCD 09, Zakopane, Poland, 8-14 February 200

    Prediction of narrow N∗N^{*} and Λ∗\Lambda^* resonances with hidden charm above 4 GeV

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    The interaction between various charmed mesons and charmed baryons are studied within the framework of the coupled channel unitary approach with the local hidden gauge formalism. Several meson-baryon dynamically generated narrow N∗N^* and Λ∗\Lambda^* resonances with hidden charm are predicted with mass above 4 GeV and width smaller than 100 MeV. The predicted new resonances definitely cannot be accommodated by quark models with three constituent quarks and can be looked for at the forthcoming PANDA/FAIR experiments.Comment: 4 pages, 3 figure

    Kˉ∗\bar K^* meson in dense matter

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    We study the properties of Kˉ∗\bar K^* mesons in nuclear matter using a unitary approach in coupled channels within the framework of the local hidden gauge formalism and incorporating the Kˉπ\bar K \pi decay channel in matter. The in-medium Kˉ∗N\bar K^* N interaction accounts for Pauli blocking effects and incorporates the Kˉ∗\bar K^* self-energy in a self-consistent manner. We also obtain the Kˉ∗\bar K^* (off-shell) spectral function and analyze its behaviour at finite density and momentum. At normal nuclear matter density, the Kˉ∗\bar K^* meson feels a moderately attractive potential while the Kˉ∗\bar K^* width becomes five times larger than in free space. We estimate the transparency ratio of the γA→K+K∗−A′\gamma A \to K^+ K^{* -} A^\prime reaction, which we propose as a feasible scenario at present facilities to detect the changes of the properties of the Kˉ∗\bar K^* meson in the nuclear medium.Comment: 26 pages, 9 figures, one new section added, version published in Phys. ReV. C, http://link.aps.org/doi/10.1103/PhysRevC.82.04521
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