We present results of simulations of the quenched quarkonium spectrum at two values of the lattice spacing and for quark masses around mc using the tadpole improved clover action. Attention is focussed on the lowest lying S and P states, and the triplet fine structure is obtained for the first time using a relativistic action. Typeset using REVTEX ∗Present Address: Department of Physics and Ast...

We consider nite lattice packings C n + K of n copies of some centrally symmetric convex body K in E d for large n. Assume that C n is a subset of a lattice , and % is at least the covering radius; namely, + %K covers the space. The parametric density (C n ; %) is deened by (C n ; %) = n V (K)=V (conv C n + %K). We show that if (C n ; %) is minimal for n large then the shape of conv C n is appr...

Recent results from the UKQCD Collaboration’s dynamical simulations are presented. The main feature of these ensembles is that they have a fixed lattice spacing and volume, but varying sea quark mass from infinite (corresponding to the quenched simulation) down to roughly that of the strange quark mass. The main aim of this work is to uncover dynamical quark effects from these “matched” ensembl...

(Day 1): References (for general background) →Varieties of lattice-ordered groups, N. R. Reilly, in Lattice-Ordered Groups, Advances and Techniques, A. M. W. Glass and W. C. Holland (eds.), Kluwer Academic Publishers, 1989. Lattice-Ordered Groups, an Introduction, M. Anderson and T. Feil, D. Reidel Pub. Co., 1988. Theory of Lattice-Ordered Groups, M. Darnel, Marcel Dekker, 1995. Partially Order...

Lattice constant, cohesive energy, direct band gap and valence band width had been calculated for grey tin by using ( CNDO-LUC ) method, then we had been making a comparison with experimental and other workers results for ( C, Si, Ge and Sn ) with zinc-blende structure in order to study the efficiency of this method. The results had showed that this method is good for lattice constant and bad f...

The positive-plaquette Manton action at weak coupling is a reasonable action for short-distance phenomena. We propose an iterative scheme for evolving this action into an effective action for longer distance scales. We report on the first step of this scheme in which we have measured “blocked” Creutz ratios with lattice spacing 2a at β = 16 on a 32 lattice and have searched for an effective act...

We present a condition for automatic O(a) improvement in twisted mass lattice QCD, using symmetries of the Symanzik effective theory. If the continuum part of the Symanzik effective theory is invariant under a particular transformation, named T1 in this report, scaling violations of all quantities invariant under T1 transformation are even in the lattice spacing a. On the other hand, quantities...

We present results for the bb̄ spectrum obtained using an O(Mbv )-correct non-relativistic lattice QCD action. Propagators are evaluated on SESAM’s three sets of dynamical gauge configurations generated with two flavours of Wilson fermions at β = 5.6. Compared to a quenched simulation at equivalent lattice spacing we find better agreement of our dynamical data with experimental results in the sp...

The ρ, K and φ decay constants and the vector current renormalization factor are studied by using an O(a2) classically-improved, tadpole-improved action. Tree-level calculations are used to show how the classical improvement of the action, involving next-nearest-neighbour timesteps, is transferred to the matrix elements. Simulations are performed on coarse lattices and compared to Wilson result...