7,893 research outputs found

    4d Index to 3d Index and 2d TQFT

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    We compute the 4d superconformal index for N=1,2 gauge theories on S^1 x L(p,1), where L(p,1) is a lens space. We find that the 4d N=1,2 index on S^1 x L(p,1) reduces to a 3d N=2,4 index on S^1 x S^2 in the large p limit, and to a 3d partition function on a squashed L(p,1) when the size of temporal S^1 shrinks to zero. As an application of our index, we study 4d N=2 superconformal field theories arising from the 6d N=(2,0) A_1 theory on a punctured Riemann surface, and conjecture the existence of a 2d Topological Quantum Field Theory on the Riemann surface whose correlation function coincides with the 4d N=2 index on S^1 x L(p,1).Comment: 24 pages, 2 figures; v2: typos corrected, refs added, discussion of L(p,q) remove

    Temporal meson correlators at finite temperature on quenched anisotropic lattice

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    We study charmonium correlators at finite temperature in quenched anisotropic lattice QCD. The smearing technique is applied to enhance the low energy part of the correlator. We use two analysis procedures: the maximum entropy method for extraction of the spectral function without assuming specific form, as an estimate of the shape of spectral function, and the χ2\chi^2 fit assuming typical forms as quantitative evaluation of the parameters associated to the forms. We find that at T0.9TcT\simeq 0.9T_c the ground state peak has almost the same mass as at T=0 and almost vanishing width. At T1.1TcT\simeq 1.1T_c, our result suggests that the correlator still has nontrivial peak structure at almost the same position as below TcT_c with finite width.Comment: Lattice 2002 Nonzero temperature 3page

    Radiation Spectra from Advection-Dominated Accretion Flows in a Global Magnetic Field

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    We calculate the radiation spectra from advection-dominated accretion flows (ADAFs), taking into account the effects of a global magnetic field. Calculation is based on the analytic model for magnetized ADAFs proposed by Kaburaki, where a large-scale magnetic field controls the accretion process. Adjusting a few parameters, we find that our model can well reproduce the observed spectrum of Sagittarius A^{*}. The result is discussed in comparison with those of well-known ADAF models, where the turbulent viscosity controls the accretion process.Comment: Accepted for publication in Ap

    Chiral symmetry and the axial nucleon to Delta(1232) transition form factors

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    We study the momentum and the quark mass dependence of the axial nucleon to Delta(1232) transition form factors in the framework of non-relativistic chiral effective field theory to leading-one-loop order. The outcome of our analysis provides a theoretical guidance for chiral extrapolations of lattice QCD results with dynamical fermions.Comment: 18 pages, 3 figure

    Measurement of the hyperfine structure of antihydrogen in a beam

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    A measurement of the hyperfine structure of antihydrogen promises one of the best tests of CPT symmetry. We describe an experiment planned at the Antiproton Decelerator of CERN to measure this quantity in a beam of slow antihydrogen atoms.Comment: 5th International Symposium on Symmetries in Subatomic Physics (SSP2012), Groningen (The Netherlands), June 18 to 22, 201
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