Wed·Aug 28, 2002Wednesday·August 28, 2002

1. 01*

   Kaon B-parameter using Overlap Fermions

   Thomas DeGrand (MILC collaboration)🇺🇸

   I present first results from an in-progress calculation of B_K in quenched approximation using overlap fermions. My particular implementation of the overlap uses a kernel with nearest and next-nearest neighbor interactions and HYP-blocked gauge connections. Matching to the continuum NDR regularization is done perturbatively. I present preliminary results at beta=5.9 and 6.1 (lattice spacings 0.125 and 0.09 fm) for quark masses, pseudoscalar decay constants, and B-parameter -- B_K(NDR(mu=2 GeV) is 0.66(3-4).

   hep-lathep-phNucl.Phys.B Proc.Suppl.(2003)·11 citations
2. 02*

   Empirical Baye's Method and Test in Very Light Quark Range from The Overlap Lattice QCD

   S.J. Dong · T. Draper · I. Horvath · Nilmani Mathur · J.B. Zhang

   Based on Bayesian theorem an empirical Baye's method is discussed. A programming chart for mass spectrum fitting is suggested. A weakly constrained way for getting priors to solve the chiral log data fitting singularity is tested.

   hep-latNucl.Phys.B Proc.Suppl.(2003)·3 citations
3. 03*

   Recent results from systematic parameterizations of Ginsparg-Wilson fermions

   Christof Gattringer (Regensburg)🇩🇪

   The Fixed Point Dirac Operator and Chirally Improved Fermions both use large numbers of gauge paths and the full Dirac structure to approximate a solution of the Ginsparg-Wilson equation. After a brief review of the two approaches we present recent results for quenched QCD with pion masses down to 210 MeV. We discuss the limits and advantages of approximate parameterizations and outline future perspectives.

   hep-lathep-phhep-thNucl.Phys.B Proc.Suppl.(2003)·25 citations
4. 04*

   Axial anomaly with the overlap-Dirac operator in arbitrary dimensions

   Takanori Fujiwara🇯🇵 · Keiichi Nagao🇯🇵 · Hiroshi Suzuki🇯🇵

   We evaluate for arbitrary even dimensions the classical continuum limit of the lattice axial anomaly defined by the overlap-Dirac operator. Our calculational scheme is simple and systematic. In particular, a powerful topological argument is utilized to determine the value of a lattice integral involved in the calculation. When the Dirac operator is free of species doubling, the classical continuum limit of the axial anomaly in various dimensions is combined into a form of the Chern character, as expected.

   hep-lathep-thJHEP(2002)·29 citations
5. 05*

   An Exact Algorithm for Any-flavor Lattice QCD with Kogut-Susskind Fermion

   JLQCD collaboration: S. Aoki🇯🇵 · M. Fukugita🇯🇵 · S. Hashimoto🇯🇵 · K-I. Ishikawa🇯🇵 · N. Ishizuka🇯🇵 · Y. Iwasaki🇯🇵 · K. Kanaya🇯🇵 · T. Kaneko🇯🇵 · Y. Kuramashi🇯🇵 · M. Okawa🇯🇵 · N. Tsutsui🇯🇵 · A. Ukawa🇯🇵 · N. Yamada🇯🇵 · T. Yoshié🇯🇵

   We propose an exact simulation algorithm for lattice QCD with dynamical Kogut-Susskind fermion in which the N_f-flavor fermion operator is defined as the N_f/4-th root of the Kogut-Susskind (KS) fermion operator. The algorithm is an extension of the Polynomial Hybrid Monte Carlo (PHMC) algorithm to KS fermions. The fractional power of the KS fermion operator is approximated with a Hermitian Chebyshev polynomial, with which we can construct an algorithm for any number of flavors. The error which arises from the approximation is corrected by the Kennedy-Kuti noisy Metropolis test. Numerical simulations are performed for the two-flavor case for several lattice parameters in order to confirm the validity and the practical feasibility of the algorithm. In particular tests on a 16^4 lattice with a quark mass corresponding to m_{PS}/m_V ~ 0.68 are successfully accomplished. We conclude that our algorithm provides an attractive exact method for dynamical QCD simulations with KS fermions.

   hep-latComput.Phys.Commun.(2003)·7 citations
6. 06*

   Hadronic Spectral Functions above the QCD Phase Transition

   M. Asakawa🇯🇵 · T. Hatsuda🇯🇵 · Y. Nakahara🇯🇵

   We extract the spectral functions in the scalar, pseudo-scalar, vector, and axial vector channels above the deconfinement phase transition temperature (Tc) using the maximum entropy method (MEM). We use anisotropic lattices, 32^3 * 32, 40, 54, 72, 80, and 96 (corresponding to T = 2.3 Tc --> 0.8 Tc), with the renormalized anisotropy xi = 4.0 to have enough temporal data points to carry out the MEM analysis. Our result suggests that the spectral functions continue to possess non-trivial structures even above Tc and in addition that there is a qualitative change in the state of the deconfined matter between 1.5 Tc and 2 Tc.

   hep-lathep-phnucl-thNPA(2003)·158 citations
7. 07*

   Large N reduction with overlap fermions

   J. Kiskis (UCD)🇺🇸 · R. Narayanan (FIU)🇺🇸 · H. Neuberger (Rutgers)🇺🇸

   We revisit quenched reduction with fermions and explain how some old problems can be avoided using the overlap Dirac operator.

   hep-lathep-thNucl.Phys.B Proc.Suppl.(2003)·2 citations
8. 08*

   Strongly coupled N=1 SYM theory on the lattice

   F. Berruto🇺🇸 · M. Schwetz🇺🇸

   We propose a strong coupling expansion as a possible tool to obtain qualitative and quantitative informations about N=1 SYM theory. We point out the existence of a mapping between strongly coupled lattice N=1 SYM theory and a generalized SO(4) antiferromagnetic spin system.

   hep-lathep-thNucl.Phys.B Proc.Suppl.(2003)·1 citation

* 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.