The dominant cutoo eeects in lattice QCD with Wilson quarks are proportional to the lattice spacing a. In particular, the isovector axial current satisses the PCAC relation only up to such eeects. Following a suggestion of Symanzik, they can be cancelled by adding local O(a) correction terms to the action and the axial current. We here address a number of theoretical issues in connection with t...

We compute the b quark mass from dynamical lattice QCD with clover quarks. The calculation is done at a fixed lattice spacing with sea quark masses as low as half the strange quark mass. Our final result is m b (m b) = 4.25(2)(11) GeV, where the first error is statistical and the last error is the systematic uncertainty.

Lattice QCD with N f = 2 flavours of sea quark is used to explore the spectrum and decay of a J P C = 1 −+ spin-exotic hybrid meson. We test lattice determination of S-wave decay amplitudes at threshold using b 1 → πω where agreement with data is found. We find a hybrid meson state at 2.2(2) GeV with a partial width to πb 1 of 400(120) MeV and to πf 1 of 90(60) MeV.

We study gluon propagator in Landau gauge with lattice QCD, where we use an improved lattice action. The calculation of gluon propagator is performed on lattices with the lattice spacing from 0.40fm to 0.24fm and with the lattice volume from (2.40fm) 4 to (4.0fm) 4. We try to fit our results by two different ways, in the first one we interpret the calculated gluon propagators as a function of t...

We review the recent advances in the calculation of the forces between hadron using lattice QCD. Particular attention is payed to the case of nuclear forces. The issues facing this project and some of the ideas put forward to solve them are briefly discussed.

The in-medium modifications of hadron properties are briefly discussed. We restrict the discussion to the lattice QCD calculations for the hadron masses, screening masses, decay constants and wave functions. We review the progress made so far and describe how to broaden its horizon.

We show that, under a reasonable " smoothness " hypothesis, it is possible to extract informations on the amplitude and phase of two-body non-leptonic weak decay matrix elements from the study of Euclidean correlation functions in lattice QCD.

Significant progress has been made since 1996 in the determination of the light quark masses from both lattice QCD (LQCD) and QCD sumrules (SR). The evolution in time of the ranges quoted by the Particle Data Group and our best estimates as of DPF2000 are given below. Since the scale dependence between 2 and 1 GeV is very large, we quote all results in the MS scheme at scale μ = 2 GeV. Results ...