210 research outputs found
Hadron Electromagnetic Structure: Shedding Light on Models and their Mechanisms
Full text linkStrange quark contributions to the proton magnetic moment are estimated from
a consideration of baryon magnetic moment sum rules. The environment
sensitivity of quark contributions to baryon moments is emphasized. Pion cloud
contributions to proton charge radii are examined in the framework of Chiral
Perturbation Theory. The absence of scalar-diquark clustering in the nucleon is
discussed.Comment: Lattice '93 presentation. UU-File is a single postscript file of a 3
page manuscript including figures. Ohio State U. PP #93-112
Essential Strangeness in Nucleon Magnetic Moments
Get PDFEffective quark magnetic moments are extracted from experimental measurements
as a function of the strangeness magnetic moment of the nucleon. Assumptions
made in even the most general quark model analyses are ruled out by this
investigation. Ab initio QCD calculations demand a non-trivial role for strange
quarks in the nucleon. The effective moments from QCD calculations are
reproduced for a strangeness magnetic moment contribution to the proton of 0.11
, which corresponds to .Comment: HYP '94 presentation. File is a uuencoded postscript file of a 2 page
manuscript including figures. Also available via anonymous ftp from
pacific.mps.ohio-state.edu in pub/NTG/Leinweber as StrQrkNmom.ps(.gz) OSU PP
#94-063
Over-Improved Stout-Link Smearing
Get PDFA new over-improved stout-link smearing algorithm, designed to stabilise
instanton-like objects, is presented. A method for quantifying the selection of
the over-improvement parameter, , is demonstrated. The new smearing
algorithm is compared with the original stout-link smearing, and Symanzik
improved smearing through calculations of the topological charge and
visualisations of the topological charge density.Comment: 9 pages, 18 figures, submitted to Physical Review
Light Hadron Spectroscopy on Coarse Lattices with O(a^2) Mean-Field Improved Actions
Get PDFThe masses and dispersions of light hadrons are calculated in lattice QCD
using an O(a^2) tadpole-improved gluon action and an O(a^2) tadpole-improved
next-nearest-neighbor fermion action originally proposed by Hamber and Wu. Two
lattices of constant volume with lattice spacings of approximately 0.40 fm and
0.24 fm are considered. The results reveal some scaling violations at the
coarser lattice spacing on the order of 5%. At the finer lattice spacing, the
calculated mass ratios reproduce state-of-the-art results using unimproved
actions. Good dispersion and rotational invariance up to momenta of pa ~ 1 are
also found. The relative merit of alternative choices for improvement operators
is assessed through close comparisons with other plaquette-based
tadpole-improved actions.Comment: 17 page RevTeX manuscript. 7 Figures. This and related papers may
also be obtained from
http://www.physics.adelaide.edu.au/~dleinweb/Publications.htm
Chiral behavior of baryon magnetic moments
Full text linkThe utility of chiral effective field theory, constructed in a manner in
which loop contributions are suppressed as one moves outside the power-counting
regime, is explored for baryon magnetic moments. Opportunities for the study of
significant chiral curvature in valence and full QCD and the nontrivial
behavior of strange- and light-quark contributions to the magnetic moment of
the Lambda baryon are highlighted.Comment: 7 pages, 5 figures; prepared for the proceedings of Achievements and
New Directions in Subatomic Physics: Workshop in Honour of Tony Thomas' 60th
Birthda
- …
