Tue·Oct 14, 2003Tuesday·October 14, 2003

1. 01*

   On the gauge dependence of the singlet and adjoint potentials

   V.A. Belavin🇷🇺 · V.G. Bornyakov🇷🇺 · V.K. Mitrjushkin🇷🇺

   We study gauge dependence of the recently suggested definition of the singlet and adjoint potentials in SU(2) lattice gauge theory. We find that in the (time local) maximal tree axial gauge the singlet potential obtained from the gauge dependent correlator $TrL(x)L^{†}(y)$ differs from that computed in the Coulomb gauge. In the generalized Coulomb gauge we find the range of the parameter values in which the singlet potential differs from that in the Coulomb gauge.

   hep-latPLB(2004)·5 citations
2. 02*

   The Study of the Continuum Limit of the Supersymmetric Ward-Takahashi Identity for N=1 Super Yang-Mills Theory

   A.Feo🇮🇪

   The one-loop corrections to the supersymmetric Ward-Takahashi identity (WTi) are investigated in the off-shell regime in the Wilson formulation of the discretized N=1 Super Yang-Mills (SYM) theory. The study of the continuum limit as well as the renormalization procedure for the supercurrent are presented.

   hep-lathep-phhep-th3 citations
3. 03*

   Non-perturbative Heavy Quark Effective Theory

   Jochen Heitger (Universitaet Muenster)🇩🇪 · Rainer Sommer (DESY Zeuthen and CERN)🇩🇪

   We explain how to perform non-perturbative computations in HQET on the lattice. In particular the problem of the subtraction of power-law divergences is solved by a non-perturbative matching of HQET and QCD. As examples, we present a full calculation of the mass of the b-quark in the combined static and quenched approximation and outline an alternative way to obtain the B-meson decay constant at lowest order. Since no excessively large lattices are required, our strategy can also be applied including dynamical fermions.

   hep-lathep-phJHEP(2004)·135 citations
4. 04*

   Non perturbative study of QCD on a 2+2 anisotropic lattice

   Giuseppe Burgio🇮🇪 · Alessandra Feo🇮🇪 · Mike Peardon🇮🇪 · Sinead M. Ryan🇮🇪

   We present preliminary results for a non perturbative determination of the parameters in the action required to restore Lorentz invariance in long distance correlators, using the static interquark potential. Comparison with analytical results is made and further applications are discussed.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·3 citations
5. 05*

   Quenched and Unquenched Chiral Perturbation Theory in the \epsilon-Regime

   P.H.Damgaard🇩🇰

   The chiral limit of finite-volume QCD is the $ϵ$-regime of the theory. We discuss how this regime can be used for determining low-energy observables of QCD by means of comparisons between lattice simulations and quenched and unquenched chiral perturbation theory. The quenched theory suffers in the $ϵ$-regime from ``quenched finite volume logs'', the finite-volume analogs of quenched chiral logs.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·10 citations
6. 06*

   A BCS Gapped Superfluid on the Lattice

   David N. Walters🇬🇧

   We discuss results of numerical analyses of the 3+1 dimensional Nambu--Jona-Lasinio model at non-zero baryon density. By studying relevant order parameters, it is shown that the model goes through a transition between a vacuum with broken chiral symmetry, and a chirally restored phase at high baryon chemical potential (mu) with a diquark condensate roughly proportional to the area of the Fermi surface and a broken U(1) baryon number symmetry. The condensation of diquark pairs from the fermionic spectrum is shown to lead to an energy gap (Delta) about the Fermi energy (E_F), which is found to be approximately 15% of the vacuum fermion mass and roughly independent of mu in the chirally restored phase. The ground-state is believed, therefore, to be that of a BCS superfluid. We also discuss the effect of simulating on a finite volume, and any caveats this places on the conclusions made above.

   hep-lathep-phnucl-thProg.Theor.Phys.Suppl.(2004)·3 citations
7. 07*

   The Harris-Luck criterion for random lattices

   Wolfhard Janke🇩🇪 · Martin Weigel🇩🇪

   The Harris-Luck criterion judges the relevance of (potentially) spatially correlated, quenched disorder induced by, e.g., random bonds, randomly diluted sites or a quasi-periodicity of the lattice, for altering the critical behavior of a coupled matter system. We investigate the applicability of this type of criterion to the case of spin variables coupled to random lattices. Their aptitude to alter critical behavior depends on the degree of spatial correlations present, which is quantified by a wandering exponent. We consider the cases of Poissonian random graphs resulting from the Voronoi-Delaunay construction and of planar, ``fat'' ${\varphi }^3$ Feynman diagrams and precisely determine their wandering exponents. The resulting predictions are compared to various exact and numerical results for the Potts model coupled to these quenched ensembles of random graphs.

   ↳ cond-mat.stat-mechcond-mat.dis-nnhep-latPRB(2004)·12 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.