Vacuum properties in the presence of quantum fluctuations of the quark condensate

The quantum fluctuations of the quark condensate are calculated using a regulated Nambu Jona-Lasinio model. The corresponding quantum fluctuations of the chiral fields are compared to those which are predicted by an ''equivalent'' sigma model. They are found to be large and comparable in size but they do not restore chiral symmetry. The restoration of chiral symmetry is prevented by an ''exchange term'' of the pion field which does not appear in the equivalent sigma model. A vacuum instability is found to be dangerously close when the model is regulated with a sharp 4-momentum cut-off.Comment: latex klein.tex, 11 files, 20 pages Workshop on Few-Quark Problems Bled, Slovenia 2000-07-08 2000-07-16 July 8-16 2000 [SPhT-T00/109

The Regularization of the Fermion Determinant in Chiral Quark Models

The momentum dependence of the quark self energy gives a physically motivated and consistent regularization of both the real and imaginary parts of the quark loop contribution to the meson action. We show that the amplitudes for anomalous processes are always reproduced correctly.Comment: 12/8 pages (b/l), plain TeX with harvmac, SphT93/13

Three New Aceria Species (Acari: Prostigmata: Eriophyoidea) from Hungary on Limonium gmelinii ssp. hungaricum (Plumbaginaceae), Petrorhagia prolifera (Caryophyllaceae) and Gypsophila paniculata (Caryophyllaceae)

Three new species of eriophyoid mite, Aceria cumanorum n. sp., associated with Limonium gmelinii ssp. hungaricum (Plumbaginaceae), Aceria feketeistvani n. sp. associated with Petrorhagia prolifera (Caryophyllaceae) and Aceria belarexi n. sp. on Gypsophila paniculata (Caryophyllaceae) are described and illustrated from Hungary. Morphological differences distinguishing these new species from similar Aceria species are discussed. In addition, new date-locality-host records for 9 eriophyoid species are given

Dual superconductor models of color confinement

The lectures, delivered at ECT (European Centre for Theoretical Studies in Nuclear Physics and Related Areas) in Trento (Italy) in 2002 and 2003, are addressed to physicists who wish to acquire a minimal background to understand present day attempts to model the confinement of quantum chromo-dynamics (QCD) in terms of dual superconductors. The lectures focus more on the models than on attempts to derive them from QCD. They discuss the Dirac theory of magnetic monopoles, the world sheet swept out by Dirac strings, deformations of Dirac strings and charge quantization, gauge fields associated to the field tensor and to the dual field tensor, the Landau-Ginzburg (Abelian Higgs) model of a dual superconductor, the flux tube joining two equal and opposite color-electric charges, the Abrikosov-Nielsen-Olesen vortex, the divergencies of the London limit, the comparison of the calculated flux tube and string tension with lattice data, duality transformations and the use of Kalb-Ramond fields, the two-potential Zwanziger formalism, abelian gauge fixing and abelian projection, the occurence of monopoles in an abelian gauge, the maximal abelian gauge, and the confinement of static SU(3) color charges.Comment: Lectures delivered at the European Centre for Theoretical Studies in Nuclear Physics and Related Areas, 2002-2003, ECT, Trento, Italy latex test2003-10-03-v2.tex, 10 files, 8 figures, 144 pages (References and minor text modifications added) http://www-spht.cea.fr/articles/T03/150

Analytic structure of meson propagators in the proper-time regularized Nambu--Jona-Lasinio model

We analyze the analytic structure of meson propagators in the Nambu--Jona-Lasinio model with a proper-time regulator. We show that the regulator produces unphysical complex singularities. As a result the naive use of the Wick rotation is no longer allowed. Formulas involving integration over mesonic momenta, such as meson-loop contributions or dispersion relations for meson Green's functions, cannot be written in usual forms.Comment: revised versio

A predictive formulation of the Nambu--Jona-Lasinio model

A novel strategy to handle divergences typical of perturbative calculations is implemented for the Nambu--Jona-Lasinio model and its phenomenological consequences investigated. The central idea of the method is to avoid the critical step involved in the regularization process, namely the explicit evaluation of divergent integrals. This goal is achieved by assuming a regularization distribution in an implicit way and making use, in intermediary steps, only of very general properties of such regularization. The finite parts are separated of the divergent ones and integrated free from effects of the regularization. The divergent parts are organized in terms of standard objects which are independent of the (arbitrary) momenta running in internal lines of loop graphs. Through the analysis of symmetry relations, a set of properties for the divergent objects are identified, which we denominate consistency relations, reducing the number of divergent objects to only a few ones. The calculational strategy eliminates unphysical dependencies of the arbitrary choices for the routing of internal momenta, leading to ambiguity-free, and symmetry-preserving physical amplitudes. We show that the imposition of scale properties for the basic divergent objects leads to a critical condition for the constituent quark mass such that the remaining arbitrariness is removed. The model become predictive in the sense that its phenomenological consequences do not depend on possible choices made in intermediary steps. Numerical results are obtained for physical quantities at the one-loop level for the pion and sigma masses and pion-quark and sigma-quark coupling constants.Comment: 38 pages, 1 figure, To appear in Phy.Rev.

MOULDED, PLASTIC PGA PACKAGES

The increase of the size of le chips and the numbers of the pins made it necessary to develop a new kind of package a couple of years ago. PGA packages have appeared and have been used. The authors of this article present a new type of plastic PGA construction. The technology of the package combines the advantages of the production of moulding technologies of packages with PWB. The new plastic PGA package has good electrical and thermal properties and it is cheap. The construction and technology used allow to meet the demands of individual consumers as well - by shortening the time from design to manufacturing. The article describes in detail the testing of the thermal properties of the plastic PGA package

Nonlocal Polyakov-Nambu-Jona-Lasinio model with wavefunction renormalization at finite temperature and chemical potential

We study the phase diagram of strongly interacting matter in the framework of a non-local SU(2) chiral quark model which includes wave function renormalization and coupling to the Polyakov loop. Both non-local interactions based on the frequently used exponential form factor, and on fits to the quark mass and renormalization functions obtained in lattice calculations are considered. Special attention is paid to the determination of the critical points, both in the chiral limit and at finite quark mass. In particular, we study the position of the Critical End Point as well as the value of the associated critical exponents for different model parameterizations.Comment: v.2_August 2010, 26 pp, 8 fi