Mon·Nov 19, 2001Monday·November 19, 2001

1. 01*

   Perturbative expansions from Monte Carlo simulations at weak coupling: Wilson loops and the static-quark self-energy

   H. D. Trottier🇨🇦 · N. H. Shakespeare🇨🇦 · G. P. Lepage🇺🇸 · P. B. Mackenzie🇺🇸

   Perturbative coefficients for Wilson loops and the static-quark self-energy are extracted from Monte Carlo simulations at weak coupling. The lattice volumes and couplings are chosen to ensure that the lattice momenta are all perturbative. Twisted boundary conditions are used to eliminate the effects of lattice zero modes and to suppress nonperturbative finite-volume effects due to Z(3) phases. Simulations of the Wilson gluon action are done with both periodic and twisted boundary conditions, and over a wide range of lattice volumes (from $3^4$ to $16^4$) and couplings (from $\beta \approx 9$ to $\beta \approx 60$). A high precision comparison is made between the simulation data and results from finite-volume lattice perturbation theory. The Monte Carlo results are shown to be in excellent agreement with perturbation theory through second order. New results for third-order coefficients for a number of Wilson loops and the static-quark self-energy are reported.

   hep-latPRD(2002)·44 citations
2. 02*

   Low-lying eigenmodes of the Wilson-Dirac operator and correlations with topological objects

   Daniel-Jens Kusterer🇦🇺 · John Hedditch🇦🇺 · Waseem Kamleh🇦🇺 · Derek B. Leinweber🇦🇺 · Anthony G. Williams🇦🇺

   The probability density of low-lying eigenvectors of the hermitian Wilson-Dirac operator is examined. Comparisons in position and size between eigenvectors, topological charge and action density are made. We do this for standard Monte-Carlo generated SU(3) background fields and for single instanton background fields. Both hot and cooled SU(3) background fields are considered. An instanton model is fitted to eigenmodes and topological charge density and the sizes and positions of these are compared.

   hep-latNPB(2002)·14 citations
3. 03*

   Low-lying fermion modes of Nf=2 improved Wilson fermions

   R. Horsley🇩🇪 · T.G. Kovacs🇩🇪 · V. Linke🇩🇪 · D. Pleiter🇩🇪 · G. Schierholz🇩🇪

   We present preliminary results for the topological charge and susceptibility determined from the low-lying eigenmodes of the Wilson-Dirac operator. These modes have been computed on dynamical configurations with Nf=2 non-perturbatively improved Wilson fermions. We compare our results with the eigenmodes of fermions in the quenched approximation.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·4 citations
4. 04*

   Instanton IR stabilization in the nonperturbative confining vacuum

   N.O. Agasian🇷🇺 · S.M. Fedorov🇷🇺

   The influence of nonperturbative fields on instantons in quantum chromodynamics is studied. Nonperturbative vacuum is described in terms of nonlocal gauge invariant vacuum averages of gluon field strength. Effective action for instanton is derived in bilocal approximation and it is demonstrated that stochastic background gluon fields are responsible for infra-red (IR) stabilization of instantons. Dependence of characteristic instanton size on gluon condensate and correlation length in nonperturbative vacuum is found. It is shown that instanton size in QCD is of order of 0.25 fm. Comparison of obtained instanton size distribution with lattice data is made.

   ↳ hep-phhep-lathep-thJHEP(2001)·17 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.