8,919 research outputs found

    Pion Polarizability in the NJL model and Possibilities of its Experimental Studies in Coulomb Nuclear Scattering

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    The charge pion polarizability is calculated in the Nambu-Jona-Lasinio model, where the quark loops (in the mean field approximation) and the meson loops (in the 1/Nc1/N_c approximation) are taken into account. We show that quark loop contribution dominates, because the meson loops strongly conceal each other. The sigma-pole contribution (mσ2t)1(m^2_\sigma-t)^{-1} plays the main role and contains strong t-dependence of the effective pion polarizability at the region t4Mπ2|t|\geq 4M_\pi^2. Possibilities of experimental test of this sigma-pole effect in the reaction of Coulomb Nuclear Scattering are estimated for the COMPASS experiment.Comment: 11 pages, 8 figure

    Strongly coupled quantum discrete Liouville theory. I: Algebraic approach and duality

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    The quantum discrete Liouville model in the strongly coupled regime, 1<c<25, is formulated as a well defined quantum mechanical problem with unitary evolution operator. The theory is self-dual: there are two exponential fields related by Hermitean conjugation, satisfying two discrete quantum Liouville equations, and living in mutually commuting subalgebras of the quantum algebra of observables.Comment: Latex2e, 20 page

    Singularities inside non-Abelian black holes

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    Singularities inside static spherically symmetric black holes in the SU(2) Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theories are investigated. Analytical formulas are presented describing oscillatory and power law metric behavior near spacelike singularities in generic solutions.Comment: REVTeX, 9 pages, 2 EPS figures, uses epsf.st

    1/N_c- expansion of the quark condensate at finite temperature

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    Previously the quark and meson properties in a many quark system at finite temperature have been studied within effective QCD approaches in the Hartree approximation. In the present paper we consider the influence of the mesonic correlations on the quark self-energy and on the quark propagator within a systematic 1/Nc1/N_c- expansion. Using a general separable ansatz for the nonlocal interaction, we derive a selfconsistent equation for the 1/Nc1/N_c correction to the quark propagator. For a separable model with cut-off formfactor, we obtain a decrease of the condensate of the order of 20\% at zero temperature. A lowering the critical temperature for the onset of the chiral restoration transition due to the inclusion of mesonic correlations is obtained what seems to be closer to the results from lattice calculations.Comment: 19 pages, REVTeX, 5 figure

    Energy Resolved Supercurrent between two superconductors

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    In this paper I study the energy resolved supercurrent of a junction consisting of a dirty normal metal between two superconductors. I also consider a cross geometry with two additional arms connecting the above mentioned junction with two normal reservoirs at equal and opposite voltages. The dependence of the supercurrent between the two superconductors on the applied voltages is studied.Comment: revtex, 7 pages, 8 figures. accepted by Phys. Rev.

    Condensation of Silica Nanoparticles on a Phospholipid Membrane

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    The structure of the transient layer at the interface between air and the aqueous solution of silica nanoparticles with the size distribution of particles that has been determined from small-angle scattering has been studied by the X-ray reflectometry method. The reconstructed depth profile of the polarizability of the substance indicates the presence of a structure consisting of several layers of nanoparticles with the thickness that is more than twice as large as the thickness of the previously described structure. The adsorption of 1,2-distearoyl-sn-glycero-3-phosphocholine molecules at the hydrosol/air interface is accompanied by the condensation of anion silica nanoparticles at the interface. This phenomenon can be qualitatively explained by the formation of the positive surface potential due to the penetration and accumulation of Na+ cations in the phospholipid membrane.Comment: 7 pages, 5 figure
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