2,809 research outputs found
Monopole Condensation and Polyakov Loop in Finite-Temperature Pure QCD
We study the relation between the abelian monopole condensation and the
deconfinement phase transition of the finite-temperature pure QCD. The
expectation value of the monopole contribution to the Polyakov loop becomes
zero when a long monopole loop is distributed uniformly in the configuration of
the confinement phase. On the other hand, it becomes non-zero when the long
monopole loop disappears in the deconfinement phase. We also discuss the
relation between the monopole behaviors and the usual interpretation of the
spontaneous breaking of Z(N) symmetry in finite-temperature SU(N) QCD. It is
found that the boundary condition of the space direction is important to
understand the Z(N) symmetry in terms of the monopoles.Comment: 3 pages, latex, 8 figures, Talk presented at LATTICE96(topology
Improved Currents for Heavy Quarks
We discuss lattice artifacts for matrix elements of hadrons containing one or
more heavy quark. In particular, we analyze interrelations between lattice
artifacts and the expansion. The implications for calculations of
heavy-light decay constants and of semi-leptonic form factors are discussed.Comment: 3 pages, no figures, uuencoded PostScript, proceedings of Lattice
'94. LaTeX at ftp://fnth06.fnal.gov/pub/Fermilab-Pub/95.00
Binding Energies in Nonrelativistic Field Theories
Relativistic corrections communicate the binding energy of a bound state to
its kinetic mass. This mechanism is reviewed and used to explain anomalous
results of Collins, Edwards, Heller, and Sloan (hep-lat/9512026), which
compared rest and kinetic masses of heavy-light mesons and quarkonia.Comment: 4 pages, 1 figure, poster presented at LATTICE96(heavy quarks
Perturbative and Non-perturbative Corrections to
It is shown that certain double ratios introduced for computing semileptonic
form factors are accurate to order , even when the action and current
are accurate to order .Comment: Lattice99(heavyquarks); 3 + epsilon pp. LaTe
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
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
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 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
Dynamics of Langevin Simulation
This chapter [of a supplement to Prog. Theo. Phys.] reviews numerical
simulations of quantum field theories based on stochastic quantization and the
Langevin equation. The topics discussed include renormalization of finite
step-size algorithms, Fourier acceleration, and the relation of the Langevin
equation to hybrid stochastic algorithms and hybrid Monte Carlo.Comment: 20 p
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
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