95 research outputs found
Renormalization of Massive Lattice Fermions
The renormalization of a general action for massive lattice fermions is
discussed. The analysis applies for all . Preliminary results for the
self energy at one loop in perturbation theory are presented.Comment: 3 pages (you guessed it: to appear in Lattice '93), uuencoded
PostScript file, FERMILAB-CONF-93/382-T and EFI 93-72. Regular PostScript
file by anonymous ftp to fnth06.fnal.gov as pub/Fermilab-Pub/93.38
A More Improved Lattice Action for Heavy Quarks
We extend the Fermilab formalism for heavy quarks to develop a more improved
action. We give results of matching calculations of the improvement couplings
at tree level. Finally, we estimate the discretization errors associated with
the new action.Comment: 3 pages, 1 figure, Lattice 2003 Tsukuba Japa
Application of heavy-quark effective theory to lattice QCD: III. Radiative corrections to heavy-heavy currents
We apply heavy-quark effective theory (HQET) to separate long- and
short-distance effects of heavy quarks in lattice gauge theory. In this paper
we focus on flavor-changing currents that mediate transitions from one heavy
flavor to another. We stress differences in the formalism for heavy-light
currents, which are discussed in a companion paper, showing how HQET provides a
systematic matching procedure. We obtain one-loop results for the matching
factors of lattice currents, needed for heavy-quark phenomenology, such as the
calculation of zero-recoil form factors for the semileptonic decays . Results for the Brodsky-Lepage-Mackenzie scale are also
given.Comment: 35 pages, 17 figures. Program LatHQ2QCD to compute matching one-loop
coefficients available at http://theory.fnal.gov/people/kronfeld/LatHQ2QCD
First results from the asymmetric O(a) improved Fermilab action
We present first results from calculations using O(a) improved (FNAL)
space-time asymmetric action on a 12^3 x 24 quenched lattice at \beta = 5.7 and
c_SW = 1.57. The asymmetry parameter is determined non-perturbatively from the
energy-momentum dispersion relation. This improvement scheme is mass dependent,
and the calculations have been done in the charm and bottom quark mass sectors
since it is at these heavier masses that the asymmetry is expected to be
relevant.Comment: 3 pp. LaTeX2e, 6PostScript figures, uses espcrc2.sty. Contribution to
Lattice99 (Pisa) proceedings (Improvement and Renormalisation
Disappearance of the Abrikosov vortex above the deconfining phase transition in SU(2) lattice gauge theory
We calculate the solenoidal magnetic monopole current and electric flux
distributions at finite temperature in the presence of a static quark antiquark
pair. The simulation was performed using SU(2) lattice gauge theory in the
maximal Abelian gauge. We find that the monopole current and electric flux
distributions are quite different below and above the finite temperature
deconfining phase transition point and agree with predictions of the
Ginzburg-Landau effective theory.Comment: 12 pages, Revtex Latex, 6 figures - ps files will be sent upon
reques
Application of heavy-quark effective theory to lattice QCD: II. Radiative corrections to heavy-light currents
We apply heavy-quark effective theory to separate long- and short-distance
effects of heavy quarks in lattice gauge theory. In this approach, the inverse
heavy-quark mass and the lattice spacing are treated as short distances, and
their effects are lumped into short-distance coefficients. We show how to use
this formalism to match lattice gauge theory to continuum QCD, order by order
in the heavy-quark expansion. In this paper, we focus on heavy-light currents.
In particular, we obtain one-loop results for the matching factors of lattice
currents, needed for heavy-quark phenomenology, such as the calculation of
heavy-light decay constants, and heavy-to-light transition form factors.
Results for the Brodsky-Lepage-Mackenzie scale are also given.Comment: 32 pages, 8 figures. v2 corrects Eqs. (4.9) and (4.10) and adds a
reference. Program LatHQ2QCD to compute matching one-loop coefficients
available at http://theory.fnal.gov/people/kronfeld/LatHQ2QCD
Estimated Errors in |Vcd|/|Vcs| from Semileptonic D Decays
We estimate statistical and systematic errors in the extraction of the CKM
ratio |Vcd|/|Vcs| from exclusive D-meson semileptonic decays using lattice QCD
and anticipated new experimental results.Comment: LATTICE98(heavyqk), LaTeX, 3 pages, 2 postscript figures, uses
espcrc2.sty and hyperbasics.te
B Mixing in the Standard Model and Beyond: Lattice QCD
We give a brief overview and progress report on our lattice QCD calculation
of neutral B mixing hadronic matrix elements needed for Standard Model and
Beyond the Standard Model physics. Reference [1] contains more details and
results.Comment: 3 pages, 0 figures, Proceedings of the 19th Particles and Nuclei
International Conference (PANIC11), Cambridge, MA, U.S.A., July 201
Effective Monopole Action at Finite Temperature in SU(2) Gluodynamics
Effective monopole action at finite temperature in SU(2) gluodynamics is
studied on anisotropic lattices. Using an inverse Monte-Carlo method and the
blockspin transformation for space directions, we determine 4-dimensional
effective monopole action at finite temperature. We get an almost perfect
action in the continuum limit under the assumption that the action is composed
of two-point interactions alone. It depends on a physical scale and the
temperature . The temperature-dependence appears with respect to the
spacelike monopole couplings in the deconfinement phase, whereas the timelike
monopole couplings do not show any appreciable temperature-dependence. The
dimensional reduction of the 4-dimensional SU(2) gluodynamics ((SU(2)))
at high temperature is the 3-dimensional Georgi-Glashow model ().
The latter is studied at the parameter region obtained from the dimensional red
uction. We compare the effective instanton action of with the
timelike monopole action obtained from (SU(2)). We find that both agree
very well for at large region. The dimensional reduction
works well also for the effective action.Comment: 34 pages, 23 figure
Continuum Gauge Fields from Lattice Gauge Fields
On the lattice some of the salient features of pure gauge theories and of
gauge theories with fermions in complex representations of the gauge group seem
to be lost. These features can be recovered by considering part of the theory
in the continuum. The prerequisite for that is the construction of continuum
gauge fields from lattice gauge fields. Such a construction, which is gauge
covariant and complies with geometrical constructions of the topological charge
on the lattice, is given in this paper. The procedure is explicitly carried out
in the theory in two dimensions, where it leads to simple results.Comment: 16 pages, HLRZ 92-3
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