159 research outputs found

    QCD Sum Rules, a Modern Perspective

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    An introduction to the method of QCD sum rules is given for those who want to learn how to use this method. Furthermore, we discuss various applications of sum rules, from the determination of quark masses to the calculation of hadronic form factors and structure functions. Finally, we explain the idea of the light-cone sum rules and outline the recent development of this approach.Comment: 84 pages, 14 figures, Latex,epsfig,sprocl.sty. To be published in the Boris Ioffe Festschrift ''At the Frontier of Particle Physics / Handbook of QCD'', edited by M. Shifman (World Scientific, Singapore, 2001)

    Exotic JPC=1+J^{PC}=1^{-+} mesons in a holographic model of QCD

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    Mesons with quantum numbers JPC=1+J^{PC}=1^{-+} cannot be represented as simple quark-antiquark pairs. We explore hybrid configurations in the light meson sector comprising a quark, an antiquark and an excited gluon, studying the properties of such states in a phenomenological model inspired by the gauge/gravity correspondence. The computed mass, compared to the experimental mass of the 1+1^{-+} candidates π1(1400)\pi_1(1400), π1(1600)\pi_1(1600) and π1(2015)\pi_1(2015), favous π1(1400)\pi_1(1400) as the lightest hybrid state. An interesting result concerns the stability of hybrid mesons at finite temperature: they disappear from the spectral function (i.e. they melt) at a lower temperature with respect to other states, light vector and scalar mesons, and scalar glueballs.Comment: 11 pages, 7 figure

    Open charm meson spectroscopy: Where to place the latest piece of the puzzle

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    We discuss how to classify the csˉc{\bar s} meson DsJ(3040)D_{sJ}(3040) recently discovered by the BaBar Collaboration. We consider four possible assignments, together with signatures useful to distinguish among them.Comment: RevTeX, 5 pages, 1 eps figur