Improving Algorithms to Compute All Elements of the Lattice Quark Propagator

We present a new exact algorithm for estimating all elements of the quark propagator. The advantage of the method is that the exact all-to-all propagator is reproduced in a large but finite number of inversions. The efficacy of the algorithm is tested in Monte Carlo simulations of Wilson quarks in quenched QCD. Applications that are difficult to probe with point propagators are discussed.Comment: Talks presented by AOC and KJJ at Lattice2004(machines), Fermilab, June 21-26, 2004. 6 pages, 6 figure

QCD on 2+2 anisotropic lattices

We discuss the implementation of QCD on 2+2 anisotropic lattices. Technical details regarding the choice of the action as well as perturbative and non-perturbative improvement are analyzed. The physical applications of the program are presented.Comment: 3 pages, 1 figure. Talk given by G. Burgio at Lattice02, MIT. To appear on Nucl. Phys. B (proc. Suppl.

Charmonium at high temperature in two-flavor QCD

We compute charmonium spectral functions in 2-flavor QCD on anisotropic lattices using the maximum entropy method. Our results suggest that the S-waves (J/psi and eta_c) survive up to temperatures close to 2Tc, while the P-waves (chi_c0 and chi_c1) melt away below 1.2Tc.Comment: 11 pages, 19 figures. v2: expanded discussion and modified conclusions. One figure changed. To appear in PR

Charmonium Spectrum on dynamical anisotropic lattices

We present a first study of the charmonium spectrum on N_f=2 dynamical, anisotropic lattices. We take advantage of all-to-all quark propagators to build spatially extended interpolating operators to increase the overlap with states not easily accessible with point propagators such as radially excited states of eta_c, psi, and chi_c, D-waves and hybrid states.Comment: 9 pages, 7 figures, Lattice 2005 Conferenc

The glueball spectrum from an anisotropic lattice study

The spectrum of glueballs below 4 GeV in the SU(3) pure-gauge theory is investigated using Monte Carlo simulations of gluons on several anisotropic lattices with spatial grid separations ranging from 0.1 to 0.4 fm. Systematic errors from discretization and finite volume are studied, and the continuum spin quantum numbers are identified. Care is taken to distinguish single glueball states from two-glueball and torelon-pair states. Our determination of the spectrum significantly improves upon previous Wilson action calculations.Comment: 14 pages, 8 figures, uses REVTeX and epsf.sty (final version published in Physical Review D

Efficient glueball simulations on anisotropic lattices

Monte Carlo results for the low-lying glueball spectrum using an improved, anisotropic action are presented. Ten simulations at lattice spacings ranging from 0.2 to 0.4 fm and two different anisotropies have been performed in order demonstrate the advantages of using coarse, anisotropic lattices to calculate glueball masses. Our determinations of the tensor (2++) and pseudovector (1+-) glueball masses are more accurate than previous Wilson action calculations.Comment: 43 pages, LaTeX (with revtex). 13 postscript figures. Submitted to Phys. Rev.

Gauge Theories on a 2+2 Anisotropic Lattice

The implementation of gauge theories on a four-dimensional anisotropic lattice with two distinct lattice spacings is discussed, with special attention to the case where two axes are finely and two axes are coarsely discretized. Feynman rules for the Wilson gauge action are derived and the renormalizability of the theory and the recovery of the continuum limit are analyzed. The calculation of the gluon propagator and the restoration of Lorentz invariance in on-shell states is presented to one-loop order in lattice perturbation theory for $SU(N_c)$ on both 2+2 and 3+1 lattices.Comment: 27 pages, uses feynmf. Font compatibility adjuste