3,325 research outputs found

    Chiral Loops and Ghost States in the Quenched Scalar Propagator

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    The scalar, isovector meson propagator is analyzed in quenched QCD, using the MQA pole-shifting ansatz to study the chiral limit. In addition to the expected short-range exponential falloff characteristic of a heavy scalar meson, the propagator also exhibits a longer-range, negative metric contribution which becomes pronounced for smaller quark masses. We show that this is a quenched chiral loop effect associated with the anomalous structure of the η′\eta ' propagator in quenched QCD. Both the time dependence and the quark mass dependence of this effect are well-described by a chiral loop diagram corresponding to an η′−π\eta '- \pi intermediate state, which is light and effectively of negative norm in the quenched approximation. The relevant parameters of the effective Lagrangian describing the scalar sector of the quenched theory are determined.Comment: 29 pages, 10 figures, Late

    Comment on covariant Stora--Zumino chain terms

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    In a recent paper, Ekstrand proposed a simple expression from which covariant anomaly, covariant Schwinger term and higher covariant chain terms may be computed. We comment on the relation of his result to the earlier work of Tsutsui.Comment: Latex file, no figure

    Low Dirac Eigenmodes and the Topological and Chiral Structure of the QCD Vacuum

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    Several lattice calculations which probe the chiral and topological structure of QCD are discussed. The results focus attention on the low-lying eigenmodes of the Dirac operator in typical gauge field configurations.Comment: Talk presented at the DPF2000 Conferenc

    Capture of non-relativistic particles in eccentric orbits by a Kerr black hole

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    We obtain approximate analytic expressions for the critical value of the total angular momentum of a non-relativistic test particle moving in the Kerr geometry, such that it will be captured by the black hole. The expressions apply to arbitrary orbital inclinations, and are accurate over the entire range of angular momentum for the Kerr black hole. The expressions can be easily implemented in N-body simulations of the evolution of star clusters around massive galactic black holes, where such captures play an important role.Comment: 8 pages, 1 figure, published versio

    Explanation of the Tao effect

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    In a series of experiments Tao and coworkers\cite{tao1,tao2,tao3} found that superconducting microparticles in the presence of a strong electrostatic field aggregate into balls of macroscopic dimensions. No explanation of this phenomenon exists within the conventional theory of superconductivity. We show that this effect can be understood within an alternative electrodynamic description of superconductors recently proposed that follows from an unconventional theory of superconductivity. Experiments to test the theory are discussed.Comment: Submitted to Science January 2nd, declined January 6th; to Nature January 7th, declined January 13th; to PRL January 14th, declined February 25t

    Relativistic Hydrodynamics with General Anomalous Charges

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    We consider the hydrodynamic regime of gauge theories with general triangle anomalies, where the participating currents may be global or gauged, abelian or non-abelian. We generalize the argument of arXiv:0906.5044, and construct at the viscous order the stress-energy tensor, the charge currents and the entropy current.Comment: 13 pages, Revte

    Neutrino masses and mixings

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    We propose a novel theoretical understanding of neutrino masses and mixings, which is attributed to the intrinsic vector-like feature of the regularized Standard Model at short distances. We try to explain the smallness of Dirac neutrino masses and the decoupling of the right-handed neutrino as a free particle. Neutrino masses and mixing angles are completely related to each other in the Schwinger-Dyson equations for their self-energy functions. The solutions to these equations and a possible pattern of masses and mixings are discussed.Comment: LaTex 11 page

    Question book of book-keeping containing all the questions and problems in the subject given at th first fifteen New York examinantions for state certificates with full answers, solutions, and entries

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    The twenty-one numbers already published of the Dime Series of Question Books have led to inquiries for similar books in many other subjects, but especially in Book-Keeping. It seems to be widely felt that its general principles and methods should be known to pupils in our common schools without the formality of a Commercial Course, and that a little manual like this may give to a well-grounded arithmetic class just about the instruction and familiarity with forms required for practical purposes. There is also a special demand for such a book to aid teachers in preparing for examinations for licenses, the higher grades of which now call for questions in this branch. To ensure completeness, all the questions in bookkeeping given at the first fifteen New York examinations for State Certificates have been inserted and fully answered. A comparison with the Civil Service examinations of the United States and of New York State shows that all important points are here sufficiently treated to cover any questions likely to be given. The Key is on pages 72, 78. In regard to forms of entries book keepers are not agreed, but those here given correspond with what seems to be the most usual practice. The principles are of course the same in all, but each book keeper may follow bis own notions as to details. The forms here given would be anywhere accepted as correct, and usually, I believe, as the best. I have consulted all the leading works on the subject, but have not followed any one of them closely enough to make special acknowledgment necessary. Language : en

    Explicit connection between conformal field theory and 2+1 Chern-Simons theory

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    We give explicit field theoretical representations for the observables of 2+1 dimensional Chern-Simons theory in terms of gauge invariant composites of 2D WZW fields. To test our identification we compute some basic Wilson loop correlators reobtaining known results.Comment: 13 pages, Latex file. To appear in Mod.Phys.Lett.

    Chiral Lagrangian Parameters for Scalar and Pseudoscalar Mesons

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    The results of a high-statistics study of scalar and pseudoscalar meson propagators in quenched lattice QCD are presented. For two values of lattice spacing, β=5.7\beta=5.7 (a≈.18a \approx .18 fm) and 5.9 (a≈.12a \approx .12 fm), we probe the light quark mass region using clover improved Wilson fermions with the MQA pole-shifting ansatz to treat the exceptional configuration problem. The quenched chiral loop parameters m0m_0 and αΦ\alpha_{\Phi} are determined from a study of the pseudoscalar hairpin correlator. From a global fit to the meson correlators, estimates are obtained for the relevant chiral Lagrangian parameters, including the Leutwyler parameters L5L_5 and L8L_8. Using the parameters obtained from the singlet and nonsinglet pseudoscalar correlators, the quenched chiral loop effect in the nonsinglet scalar meson correlator is studied. By removing this QCL effect from the lattice correlator, we obtain the mass and decay constant of the ground state scalar, isovector meson a0a_0.Comment: 36 pages, 12 figures, LaTe
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