Mon·Aug 22, 2005Monday·August 22, 2005

1. 01*

   Overlap hypercube fermions in QCD with light quarks

   W. Bietenholz🇩🇪 · S. Shcheredin🇩🇪

   We report on simulation results with overlap hypercube fermions (overlap HF) - a type of exactly chiral lattice fermions - and their link to chiral perturbation theory. We first sketch the construction of the overlap HF and discuss its high level of locality. Next we show applications in the p-regime of QCD, where we evaluate m_{\pi}, m_{\rho}, the quark mass according to the PCAC relation, the renormalisation constant Z_A and the pion decay constant F_{\pi} as functions of the bare quark mass. F_{\pi} is then reconsidered at even smaller quark masses in the epsilon-regime, along with the scalar condensate \Sigma. In that context we also discuss results for the topological charges and susceptibility.

   hep-latPoS(2006)·10 citations
2. 02*

   Symmetry and scaling in the Q-exact lattice (2,2) 2d Wess-Zumino model

   Joel Giedt🇨🇦

   As a nonperturbative check on the Q-exact lattice formulation, we demonstrate that the continuum R-symmetries are recovered. We locate the critical domain of the lattice theory. Aspects of the continuum nonrenormalization theorems are found to be respected at finite lattice spacing. Preliminary attempts to extract critical exponents--another nonperturbative check--are discussed. All of our results are obtained from Monte Carlo simulations with dynamical fermions.

   hep-latPoS(2006)·1 citation
3. 03*

   Clebsch-Gordan Construction of Lattice Interpolating Fields for Excited Baryons

   Subhasish Basak🇺🇸 · Robert Edwards🇺🇸 · George T. Fleming🇺🇸 · Urs M. Heller🇺🇸 · Colin Morningstar🇺🇸 · David Richards🇺🇸 · Ikuro Sato🇺🇸 · Stephen J. Wallace🇺🇸

   Large sets of baryon interpolating field operators are developed for use in lattice QCD studies of baryons with zero momentum. Operators are classified according to the double-valued irreducible representations of the octahedral group. At first, three-quark smeared, local operators are constructed for each isospin and strangeness and they are classified according to their symmetry with respect to exchange of Dirac indices. Nonlocal baryon operators are formulated in a second step as direct products of the spinor structures of smeared, local operators together with gauge-covariant lattice displacements of one or more of the smeared quark fields. Linear combinations of direct products of spinorial and spatial irreducible representations are then formed with appropriate Clebsch-Gordan coefficients of the octahedral group. The construction attempts to maintain maximal overlap with the continuum SU(2) group in order to provide a physically interpretable basis. Nonlocal operators provide direct couplings to states that have nonzero orbital angular momentum.

   hep-latPRD(2005)·142 citations
4. 04*

   Baryons with Ginsparg-Wilson quarks in a staggered sea

   Brian C. Tiburzi🇺🇸

   We determine the masses and magnetic moments of the octet baryons in chiral perturbation theory formulated for a mixed lattice action of Ginsparg-Wilson valence quarks and staggered sea quarks. Taste-symmetry breaking does not occur at next-to-leading order in the combined lattice-spacing and chiral expansion. Expressions derived for masses and magnetic moments are required for addressing lattice artifacts in mixed-action simulations of these observables.

   hep-lathep-phnucl-thPRD(2005)·59 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.