Thu·Aug 26, 2004Thursday·August 26, 2004

1. 01*

   Calorons with non-trivial holonomy on and off the lattice

   Falk Bruckmann🇳🇱 · E.M. Ilgenfritz🇩🇪 · B.V. Martemyanov🇷🇺 · M. Muller-Preussker🇩🇪 · Daniel Nogradi🇳🇱 · Dirk Peschka🇩🇪 · Pierre van Baal🇳🇱

   We discuss recent solutions for SU(2) calorons with non-trivial holonomy at higher charge, both through analytic means and using cooling, as well as extensive lattice studies for SU(3).

   hep-lathep-phhep-thNucl.Phys.B Proc.Suppl.(2005)·14 citations
2. 02*

   A model independent determination of $|V_{ub}|$ using the global $q^2$ dependence of the dispersive bounds on the $B\to \pi l\nu$ form factors

   Masaru Fukunaga🇯🇵 · Tetsuya Onogi🇯🇵

   We propose a method to determine the CKM matrix element $|V_{ub}|$ using the global $q^2$ dependence of the dispersive bound on the form factors for $B\to \pi l\nu$ decay. Since the lattice calculation of the $B\to \pi l\nu$ form factor is limited to the large $q^2$ regime, only the experimental data in a limited kinematic range can be used in a conventional method. In our new method which exploits the statistical distributions of the dispersive bound proposed by Lellouch, we can utilize the information of the global $q^2$ dependence for all kinematic range. As a feasibility study we determine $|V_{ub}|$ by combining the form factors from quenched lattice QCD, the dispersive bounds, and the experimental data by CLEO. We show that the accuracy of $|V_{ub}|$ can be improved by our method.

   hep-lathep-exhep-phPRD(2005)·20 citations
3. 03*

   Preliminary results of the heavy-light meson spectrum using chirally improved light quarks

   Tommy Burch🇩🇪 · Christof Gattringer🇩🇪 · Andreas Schäfer🇩🇪

   Using a ``wall'' of quark point sources, we invert the chirally improved Dirac operator to create an ``incoherent'' collection of quark propagators which originate from all spatial points of the source time slice. The lowest-order NRQCD approximation is used to create heavy-quark propagators from the same wall source. However, since the numerical cost involved in computing such heavy-quark propagators is low, we are able to use a number of source gauge paths to establish coherence between the heavy and light quarks at several spatial separations. The resulting collection of heavy-light meson correlators is analyzed to extract the corresponding mass spectrum.

   hep-lathep-phNucl.Phys.B Proc.Suppl.(2005)·6 citations
4. 04*

   A comparative study of overlap and staggered fermions in the Schwinger model

   Stephan Dürr🇩🇪 · Christian Hoelbling🇫🇷

   We investigate the validity of the square rooting procedure of the staggered determinant in the context of the Schwinger model. We find some evidence that at fixed physical quark mass the square root of the staggered determinant becomes proportional to the overlap determinant in the continuum limit. We also find that at fixed lattice spacing moderate smearing dramatically improves the chiral behavior of staggered fermions.

   hep-latNucl.Phys.B Proc.Suppl.(2005)·8 citations
5. 05*

   Finite volume effects using lattice chiral perturbation theory

   Bugra Borasoy🇩🇪 · Randy Lewis🇨🇦 · Daniel Mazur🇨🇦

   Lattice regularization is used to perform chiral perturbation theory calculations in finite volume. The lattice spacing is chosen small enough to be irrelevant, and numerical results are obtained from simple summations.

   hep-lathep-phnucl-thNucl.Phys.B Proc.Suppl.(2005)·4 citations
6. 06*

   Finite Size Scaling, Fisher Zeroes and N=4 Super Yang-Mills

   P.R. Crompton🇩🇪 · W. Janke🇩🇪 · Z.X. Xu🇨🇳 · H.P. Ying🇨🇳

   We investigate critical slowing down in the local updating continuous-time Quantum Monte Carlo method by relating the finite size scaling of Fisher Zeroes to the dynamically generated gap, through the scaling of their respective critical exponents. As we comment, the nonlinear sigma model representation derived through the hamiltonian of our lattice spin model can also be used to give a effective treatment of planar anomalous dimensions in N=4 SYM. We present scaling arguments from our FSS analysis to discuss quantum corrections and recent 2-loop results, and further comment on the prospects of extending this approach for calculating higher twist parton distributions.

   hep-latcond-mat.stat-mechhep-thNucl.Phys.B Proc.Suppl.(2005)·3 citations
7. 07*

   Temperature Dependence of Gluon and Ghost Propagators in Landau-Gauge Yang-Mills Theory below the Phase Transition

   Burghard Gruter🇩🇪 · Reinhard Alkofer🇩🇪 · Axel Maas🇩🇪 · Jochen Wambach🇩🇪

   The Dyson-Schwinger equations of Landau-gauge Yang-Mills theory for the gluon and ghost propagators are investigated. Numerical results are obtained within a truncation scheme which has proven to be successful at vanishing temperature. For temperatures up to 250 MeV we find only minor quantitative changes in the infrared behaviour of the gluon and ghost propagators. The effective action calculated from these propagators is temperature-independent within the numerical uncertainty.

   ↳ hep-phhep-latnucl-thEPJC(2005)·29 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.