Thu·Nov 22, 2001Thursday·November 22, 2001

1. 01*

   Analytic progress on exact lattice chiral symmetry

   Yoshio Kikukawa🇯🇵

   Theoretical issues of exact chiral symmetry on the lattice are discussed and related recent works are reviewed. For chiral theories, the construction with exact gauge invariance is reconsidered from the point of view of domain wall fermion. The issue in the construction of electroweak theory is also discussed. For vector-like theories, we discuss unitarity (positivity), Hamiltonian approach, and several generalizations of the Ginsparg-Wilson relation (algebraic and odd-dimensional).

   hep-latNucl.Phys.B Proc.Suppl.(2002)·12 citations
2. 02*

   On the lattice construction of electroweak gauge theory

   Yoshio Kikukawa🇯🇵 · Yoichi Nakayama🇯🇵 · Hiroshi Suzuki🇯🇵

   Based on the Ginsparg-Wilson relation, a gauge invariant formulation of electroweak SU(2)xU(1) gauge theory on the lattice is considered. If the hypercharge gauge coupling is turned off in the vacuum sector of the U(1) gauge fields, the theory consists of four left-handed SU(2) doublets and it is possible, as in vector-like theories, to make the fermion measure defined globally in all topological sectors of SU(2). We then try to incorporate U(1) gauge field, following Lüscher's reconstruction theorem. The global integrability condition is proved for ``gauge loops'' in the space of the U(1) gauge fields with arbitrary SU(2) gauge field fixed in the background. For ``non-gauge loops'', however, the proof is given so far only for the classical SU(2) instanton backgrounds.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·6 citations
3. 03*

   Effective Theories of Confinement

   L. Dittmann🇩🇪 · T. Heinzl🇩🇪 · A. Wipf🇩🇪

   We review some approaches to describe confinement in terms of effective (model) field theories. After a brief discussion of the dual Abelian Higgs model, we concentrate on a lattice analysis of the Faddeev-Niemi effective action conjectured to describe the low-lying excitations of SU(2) gluodynamics. We generalize the effective action such that it contains all operators built from a unit color vector field n with O(3) symmetry and maximally four derivatives. To avoid the presence of Goldstone bosons, we include explicit symmetry breaking terms parametrized by an external field h of mass-dimension two. We find a mass gap of the order of 1.5 GeV.

   hep-lathep-thNucl.Phys.B Proc.Suppl.(2002)·15 citations
4. 04*

   Parallel tempering in full QCD with Wilson fermions

   E.-M. Ilgenfritz🇯🇵 · W. Kerler🇩🇪 · M. Muller-Preussker🇩🇪 · H. Stuben🇩🇪

   We study the performance of QCD simulations with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering on $10^4$ and $12^4$ lattices. In order to compare tempered with standard simulations, covariance matrices between sub-ensembles have to be formulated and evaluated using the general properties of autocorrelations of the parallel tempering algorithm. We find that rendering the hopping parameter $\kappa$ dynamical does not lead to an essential improvement. We point out possible reasons for this observation and discuss more suitable ways of applying parallel tempering to QCD.

   hep-latPRD(2002)·9 citations
5. 05*

   Color-Flavor Transformation for the Special Unitary Group

   B. Schlittgen🇺🇸 · T. Wettig🇺🇸

   We extend Zirnbauer's color-flavor transformation in the fermionic sector to the case of the special unitary group. The transformation allows a certain integral over SU(N_c) color matrices to be transformed into an integral over flavor matrices which parameterize the coset space U(2N_f)/U(N_f)xU(N_f). Integrals of the type considered appear, for example, in the partition function of lattice gauge theory.

   hep-latcond-mathep-thNPB(2002)·14 citations
6. 06*

   epsilon'/eps in the Standard Model

   I. Scimemi🇪🇸 · E. Pallante🇮🇹 · A. Pich🇪🇸

   We overview the detailed analysis of epsilon'/epsilon within the Standard Model, presented in ref. 1. When all sources of large logarithms are considered, both at short and long distances, it is possible to perform a reliable Standard Model estimate of epsilon'/epsilon. The strong S-wave rescattering of the final pions has an important impact on this observable. The Standard Model prediction is found to be Re(epsilon'/epsilon) =(1.7 +- 0.9)*10^{-3}, in good agreement with the most recent experimental measurements. A better estimate of the strange quark mass would reduce the uncertainty to about 30%.

   ↳ hep-phhep-exhep-latPoS(2001)·2 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.