A review of heavy-heavy spectroscopy

Calculations of the heavy-heavy spectrum present a good opportunity for precision tests of QCD using lattice techniques. All methods make use of a non-relativistic expansion of the action and its systematic improvement to remove lattice artefacts. There was convincing demonstration this year that these methods work and that the associated perturbation theory is well-behaved. Comparison to experimental results yields an accurate value for the lattice spacing, a, a key result in the determination of \alpha_{s}, and (for the first time this year) the mass of the b quark (4.7(1) GeV).Comment: talk at Lattice'93, Dallas. 6 pages of latex espcrc2.sty needed and figures on reques

Non-Perturbative Improvement of the Anisotropic Wilson QCD Action

We describe the first steps in the extension of the Symanzik O($a$) improvement program for Wilson-type quark actions to anisotropic lattices, with a temporal lattice spacing smaller than the spatial one. This provides a fully relativistic and computationally efficient framework for the study of heavy quarks. We illustrate our method with accurate results for the quenched charmonium spectrum.Comment: LATTICE98(improvement), 3 pages, 4 figure

Moving NRQCD

I discuss the derivation and applications of Moving NRQCD (MNRQCD), a generalization of NRQCD which allows the treatment of heavy quarks moving with a finite velocity. This formalism is vital in reducing discretization errors in calculations of large recoil decays, such as B --> K^* + gamma or the Isgur-Wise function at large w.Comment: 3 pages, LaTex, uses espcrc2.sty. Talk presented at Lattice 9

Latest Results from Heavy Quark Simulations

The status of b-bbar and c-cbar calculations, numerical and analytic, are reviewed. The extraction of alpha_s and quark masses from spectrum calculations is discussed. The NRQCD and Improved Heavy Wilson formulations of heavy quarks are compared, and recent calculations using a Heavy Staggered formulation are discussed.Comment: 15 pages, latex, 9 postscript figures, self-unpacking uuencoded compressed file, requires espcrc2.sty (included) and epsf.sty. Contribution to Lattice '9

Lattice QCD on Small Computers

We demonstrate that lattice QCD calculations can be made $10^3$--$10^6$ times faster by using very coarse lattices. To obtain accurate results, we replace the standard lattice actions by perturbatively-improved actions with tadpole-improved correction terms that remove the leading errors due to the lattice. To illustrate the power of this approach, we calculate the static-quark potential, and the charmonium spectrum and wavefunctions using a desktop computer. We obtain accurate results that are independent of the lattice spacing and agree well with experiment.Comment: 15 pages, 3 figs incl as LaTex pictures Minor additions to tables and tex

fBf_B and fBsf_{B_s} using NRQCD

This talk summarizes the quenched calculation of $f_B$ and $f_{B_s}$ presented in hep-lat/9801038. The heavy quark is simulated using an $O(1/M^2)$ improved NRQCD action, and the tadpole improved clover action is used for the light quarks. The axial current includes the $O(1/M)$ corrections in one-loop perturbation theory and the $O(1/M^2)$ ones at tree-level. We discuss the various systematic effects and consistency checks made in the calculation.Comment: 3 pages. Makefile and sources included. Talk presented at LATTICE98 (HEAVYQK

Semileptonic B Decays from an NRQCD/D234 Action

Semileptonic B decays are studied on quenched anisotropic lattices using Symanzik improved glue, NRQCD heavy quark and D234 light quark actions. We employ constrained fits to extract ground state contributions to two- and three-point correlators. Results for the B --> pi, l nubar decay form factors are compared with previous lattice results. We find that our systematic errors (excluding quenching errors) are dominated by chiral extrapolation uncertainties.Comment: Lattice2002(Heavy quark physics

P-wave meson properties with Wilson quarks

We describe two calculations involving P-wave mesons made of Wilson quarks: the strong coupling constant $\alpha_s$ in the presence of two flavors of light dynamical fermions and the mass and decay constant of the $a_1$ meson.Comment: Poster presented at Lattice '94, September 27--October 1, 1994, Bielefeld, Germany (no changes to manuscript, but correction of Authors list above

Four-momentum boosted Fermion fields

A formulation of the fermion action is discussed which includes an explicit four momentum boost on the field prior to discretisation. This is used to shift the zero of lattice momentum to lie near one of the on-shell quark poles. The positive pole is selected if we wish to describe a valence quark, and negative pole for a valence anti-quark. Like NRQCD, the typical lattice momenta involved in hadronic correlation functions can be kept small: of order $O(a \Lambda_{\rm QCD})$, rather than $O(a m_Q)$ even when describing heavy quarks. If we expand around the particle pole, the anti-particle correlator will be poorly described for large $a m_Q$. However, in that case the anti-particle will be far off shell and will only affect unphysical, renormalization factors. The formulation produces the correct continuum limit, and preliminary results have been obtained (for an unimproved action) of both the one-loop self energy and a non-perturbative correlation function.Comment: Talk presented at Lattice2003(heavy). 3 pages, 1 figur

A Study of PCAC for the Nonperturbative Improvement of the Wilson Action

We present an exploratory study for the nonperturbative determination of the coefficient of the ${\cal O}(a)$ improvement term to the Wilson action, $c_{SW}$. Following the work by L\"{u}scher et al., we impose the PCAC relation as a nonperturbative improvement condition on $c_{SW}$, without, however, using the Schr\"{o}dinger functional in our calculation.Comment: 3 pages, LaTeX (uses espcrc2.sty), 4 postscript figures, to be published in the proceedings of Lattice'9