Fri·Aug 23, 2002Friday·August 23, 2002

1. 01*

   Matching coefficients for improved staggered bilinears

   Weonjong Lee🇰🇷 · Stephen R. Sharpe🇺🇸

   We calculate one-loop matching factors for bilinear operators composed of improved staggered fermions. We compare the results for different improvement schemes used in the recent literature, including the HYP action and an action close to the Asqtad action. We find that all improvement schemes substantially reduce the size of the one-loop contributions to matching factors. The resulting corrections are comparable to, or smaller than, those found with Wilson and domain-wall fermions.

   hep-latNucl.Phys.B Proc.Suppl.(2003)·10 citations
2. 02*

   Towards the Continuum Limit of the Overlap Quark Propagator in Landau Gauge

   J. B. Zhang🇦🇺 · F. D. R. Bonnet🇦🇺 · P. O. Bowman🇺🇸 · D. B. Leinweber🇦🇺 · A. G. Williams🇦🇺

   The properties of the momentum space quark propagator in Landau gauge are examined for the overlap quark action in quenched lattice QCD. Numerical calculations were done on two lattices with different lattice spacing $a$ and similar physical volumes to explore the quark propagator in the continuum limit. We have calculated the nonperturbative wavefunction renormalization function $Z(p)$ and the nonperturbative mass function $M(p)$ for a variety of bare quark masses and perform a simple linear extrapolation to the chiral limit. We find the behaviour of $Z(p)$ and $M(p)$ in the chiral limit are in good agreement between the two lattices.

   hep-latNucl.Phys.B Proc.Suppl.(2003)·17 citations
3. 03*

   $B^0-{\bar{B}}^0$ mixing in quenched lattice QCD

   JLQCD Collaboration: S. Aoki🇯🇵 · M. Fukugita🇯🇵 · S. Hashimoto🇯🇵 · K-I. Ishikawa🇯🇵 · N. Ishizuka🇯🇵 · Y. Iwasaki🇯🇵 · K. Kanaya🇯🇵 · T. Kaneko🇯🇵 · Y. Kuramashi🇯🇵 · M. Okawa🇯🇵 · T. Onogi🇯🇵 · N. Tsutsui🇯🇵 and 3 other authors

   We present our results of lattice calculations of $B$ parameters, which parameterize $\Delta B$=2 transition amplitudes together with the leptonic decay constant. Calculations are made in the quenched approximation at $\beta$=5.7, 5.9, 6.0 and 6.1, using NRQCD action for heavy quark and the $O(a)$-improved Wilson action for light quark. The operators are perturbatively renormalized including the correction of $O({\alpha }_s/(aM{)}^m)$ ($m\ge$0). We examine the scaling behavior of $B$ parameters, and discuss the systematic uncertainties based on the results with several different truncations of higher order terms in 1/M and ${\alpha }_s$ expansions. We find $B_{B_d}(m_b)=0.84(3)(5)$, $B_{B_s}/B_{B_d}=1.020(21){(}_{-16}^{+15}){(}_{-0}^{+5})$ and $B_{S_s}(m_b)=0.85(1)(5){(}_{-0}^{+1})$ in the quenched approximation. The errors represent statistical and systematic as well as the uncertainty in the determination of strange quark mass.

   hep-latPRD(2003)·36 citations
4. 04*

   A Linux PC cluster for lattice QCD with exact chiral symmetry

   Ting-Wai Chiu🇹🇼 · Tung-Han Hsieh🇹🇼 · Chao-Hsi Huang🇹🇼 · Tsung-Ren Huang🇹🇼

   A computational system for lattice QCD with exact chiral symmetry is described. The platform is a home-made Linux PC cluster, built with off-the-shelf components. At present this system constitutes of 64 nodes, with each node consisting of one Pentium 4 processor (1.6/2.0/2.5 GHz), one Gbyte of PC800/PC1066 RDRAM, one 40/80/120 Gbyte hard disk, and a network card. The computationally intensive parts of our program are written in SSE2 codes. The speed of this system is estimated to be 70 Gflops, and its price/performance is better than $1.0/Mflops for 64-bit (double precision) computations in quenched QCD. We discuss how to optimize its hardware and software for computing quark propagators via the overlap Dirac operator.

   hep-latphysics.comp-phInt.J.Mod.Phys.C(2003)·5 citations
5. 05*

   A Lattice Fermion Doublet With A Generalization Of The Ginsparg-Wilson Relation

   I. Schmelzer🇩🇪

   We present a new staggered discretization of the Dirac operator. In comparison with standard staggered fermions, real and imaginary parts are located in different nodes. Doubling gives only a doublet of Dirac fermions which we propose to interpret as a physical (lepton or quark) doublet. Contrary to usual staggered fermions, we have no exact chiral symmetry but obtain a generalization of the Ginsparg-Wilson relation.

   hep-lat1 citation
6. 06*

   Light hadron properties with improved staggered quarks

   C. Bernard🇺🇸 · T. Burch🇺🇸 · T. DeGrand🇺🇸 · C. DeTar🇺🇸 · Steven Gottlieb🇺🇸 · E.B. Gregory🇺🇸 · U.M. Heller🇺🇸 · J. Osborn🇺🇸 · R. Sugar🇺🇸 · D. Toussaint🇺🇸

   Preliminary results from simulations with 2+1 dynamical quark flavors at a lattice spacing of 0.09 fm are combined with earlier results at a=0.13 fm. We examine the approach to the continuum limit and investigate the dependence of the pseudoscalar masses and decay constants as the sea and valence quark masses are separately varied.

   hep-latNucl.Phys.B Proc.Suppl.(2003)·12 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.