129 research outputs found
Recent Developments in Lattice QCD
Recent trends in lattice QCD calculations and latest results are reviewed,
with particular emphasis on multiquark-states and the nucleon structure.Comment: Plenary Talk presented at European Few Body 19, 23-27 August 2004,
Groningen, 7 pages, 4 figure
The DsJ(2317): what can the Lattice say?
We present lattice results on the scalar meson and comment on the
state recently discovered by BaBar and confirmed by CLEO, in
view of a series of theoretical claims and counter claims. Lattice predictions
in the static limit indicate larger masses than observed for a scalar quark
model state. Finite quark mass corrections seem to further enlarge this
discrepancy, in support of a non quark-antiquark-state interpretation of
experiment.Comment: 4 pages, 1 Figur
QCD Phenomenology of Static Sources
We discuss the spectrum of open string and point particle excitations in QCD
with various source representations. Some general relations are introduced and
lattice results presented. In particular we discuss the short-distance
behaviour, relate this to perturbation theory expectations and comment on the
matching between low energy matrix elements and high energy Wilson
coefficients, within the framework of effective field theories.Comment: Invited Talk presented at LightCone 2004, 16-20 August 2004,
Amsterdam, 10 page
"Glueballs": results and perspectives from the lattice
I review the present status of lattice calculations of properties of
gluon-rich hadrons and comment on future prospects, in view of planned
experiments.Comment: 4 pages, 1 Figure, Talk presented at Photon 2001, Ascona, CH, 2.9. -
7.9.0
Baryons on the lattice
I comment on progress of lattice QCD techniques and calculations. Recent
results on pentaquark masses as well as of the spectrum of excited baryons are
summarizned and interpreted. The present state of calculations of quantities
related to the nucleon structure and of electromagnetic transition form factors
is surveyed.Comment: 10 pages, Plenary talk at 10th International Conference on Structure
of Baryons (Baryons 2004), Palaiseau, France, 25-29 Oct 2004, 1 reference
added, minor improvement
Non-perturbative determination of improvement coefficients using coordinate space correlators in lattice QCD
We determine quark mass dependent order improvement terms of the form
for non-singlet scalar, pseudoscalar, vector and axialvector currents
using correlators in coordinate space on a set of CLS ensembles. These have
been generated employing non-perturbatively improved Wilson Fermions and the
tree-level L\"uscher-Weisz gauge action at and ,
corresponding to lattice spacings ranging from fm down to
fm. In the flavour theory two types of improvement
coefficients exist: , proportional to non-singlet quark mass combinations,
and (or ), proportional to the trace of the quark mass
matrix. Combining our non-perturbative determinations with perturbative
results, we quote Pad\'e approximants parameterizing the improvement
coefficients within the above window of lattice spacings. We also give
preliminary results for at .Comment: 15 pages, 6 figures, version published in PR
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