Lattice QCD Calculations of Leptonic and Semileptonic Decays

In lattice QCD, obtaining properties of heavy-light mesons has been easier said than done. Focusing on the $B$ meson's decay constant, it is argued that towards the end of 1997 the last obstacles were removed, at least in the quenched approximation. These developments, which resulted from a fuller understanding and implementation of ideas in effective field theory, bode well for current studies of neutral meson mixing and of semileptonic decays.Comment: Invited talk at the Workshop on Heavy Quarks at Fixed Target, October 10-12, 1998, Fermi National Accelerator Laborator

B and D Mesons in Lattice QCD

Computational and theoretical developments in lattice QCD calculations of B and D mesons are surveyed. Several topical examples are given: new ideas for calculating the HQET parameters \bar{\Lambda} and \lambda_1; form factors needed to determine |V_{cb}| and |V_{ub}|; bag parameters for the mass differences of the B mesons; and decay constants. Prospects for removing the quenched approximation are discussed.Comment: Mini-review from the XXXth International Conference on High Energy Physics, Osaka, Japa

Heavy Quarks and Lattice QCD

This paper is a review of heavy quarks in lattice gauge theory, focusing on methodology. It includes a status report on some of the calculations that are relevant to heavy-quark spectroscopy and to flavor physics.Comment: Lattice2003(plenary), 14 pages, 5 figure

Lattice QCD and the Unitarity Triangle

Theoretical and computational advances in lattice calculations are reviewed, with focus on examples relevant to the unitarity triangle of the CKM matrix. Recent progress in semi-leptonic form factors for B -> pi l nu and B -> D* l nu, as well as the parameter \xi in B-Bbar mixing, are highlighted.Comment: Invited talk at the 9th International Symposium on Heavy Flavor Physics, September 10-13, 2001, Caltech, Pasadena. 11 pages, 5 figure

Lattice Gauge Theory and the Origin of Mass

Most of the mass of everyday objects resides in atomic nuclei; the total of the electrons' mass adds up to less than one part in a thousand. The nuclei are composed of nucleons---protons and neutrons---whose nuclear binding energy, though tremendous on a human scale, is small compared to their rest energy. The nucleons are, in turn, composites of massless gluons and nearly massless quarks. It is the energy of these confined objects, via $M=E/c^2$, that is responsible for everyday mass. This article discusses the physics of this mechanism and the role of lattice gauge theory in establishing its connection to quantum chromodynamics.Comment: prepared for "100 Years of Subatomic Physics," edited by Ernest Henley and Stephen Ellis. Submitted version with typos corrected and refs added. 26 pp., 6 figure

Progress in Lattice QCD

After reviewing some of the mathematical foundations and numerical difficulties facing lattice QCD, I review the status of several calculations relevant to experimental high-energy physics. The topics considered are moments of structure functions, which may prove relevant to search for new phenomena at the LHC, and several aspects of flavor physics, which are relevant to understanding CP and flavor violation.Comment: Invited talk at the XXII Physics in Collisions Conference (PIC02), Stanford, Ca, USA, June 2002, 15+1 pp. PSN FRBT0

Twenty-first Century Lattice Gauge Theory: Results from the QCD Lagrangian

Quantum chromodynamics (QCD) reduces the strong interactions, in all their variety, to a simple nonabelian gauge theory. It clearly and elegantly explains hadrons at short distances, which has led to its universal acceptance. Since its advent, however, many of its long-distance, emergent properties have been believed to be true, without having been demonstrated to be true. This paper reviews a variety of results in this regime that have been established with lattice gauge theory, directly from the QCD Lagrangian. This body of work sheds light on the origin of hadron masses, its interplay with dynamical symmetry breaking, as well as on other intriguing features such as the phase structure of QCD. In addition, nonperturbative QCD is quantitatively important to many aspects of particle physics (especially the quark flavor sector), nuclear physics, and astrophysics. This review also surveys some of the most interesting connections to those subjects.Comment: invited review for Annual Reviews of Nuclear and Particle Science (2012); 21 pp., 4 tables, 6 figures. v2: Figures 2 and 5 updated; references added; many minor wording changes and clarifications; conforms closely to accepted versio