205 research outputs found
A non-perturbative study of the action parameters for anisotropic-lattice quarks
A quark action designed for highly anisotropic lattice simulations is
discussed. The mass-dependence of the parameters in the action is studied and
the results are presented. Applications of this action in studies of heavy
quark quantities are described and results are presented from simulations at an
anisotropy of six, for a range of quark masses from strange to bottom.Comment: 9 pages, 8 figure
Static-light hadrons on a dynamical anisotropic lattice
We present preliminary results for the static-light meson and baryon spectra
for QCD. The study is performed on an anisotropic lattice and uses a
new all-to-all propagator method allowing us to determine particle masses to a
high precision.Comment: 6 pages, Contribution to Lattice2005, PoS styl
Improving Algorithms to Compute All Elements of the Lattice Quark Propagator
We present a new exact algorithm for estimating all elements of the quark
propagator. The advantage of the method is that the exact all-to-all propagator
is reproduced in a large but finite number of inversions. The efficacy of the
algorithm is tested in Monte Carlo simulations of Wilson quarks in quenched
QCD. Applications that are difficult to probe with point propagators are
discussed.Comment: Talks presented by AOC and KJJ at Lattice2004(machines), Fermilab,
June 21-26, 2004. 6 pages, 6 figure
The spectrum of radial, orbital and gluonic excitations of charmonium
We present results for the charmonium spectrum from dynamical QCD
simulations on anisotropic lattices. Using all-to-all
propagators we determine the ground and excited states of S, P and D waves and
hybrids. We also evaluate the disconnected (OZI suppressed) contribution to the
and Comment: 6 pages, 3 figures, Presented at 24th International Symposium on
Lattice Field Theory (Lattice 2006), Tucson, Arizona, 23-28 Jul 200
Isolating Excited States of the Nucleon in Lattice QCD
We discuss a robust projection method for the extraction of excited-state
masses of the nucleon from a matrix of correlation functions. To illustrate the
algorithm in practice, we present results for the positive parity excited
states of the nucleon in quenched QCD. Using eigenvectors obtained via the
variational method, we construct an eigenstate-projected correlation function
amenable to standard analysis techniques. The method displays its utility when
comparing results from the fit of the projected correlation function with those
obtained from the eigenvalues of the variational method. Standard nucleon
interpolators are considered, with and correlation
matrix analyses presented using various combinations of source-smeared,
sink-smeared and smeared-smeared correlation functions. Using these new robust
methods, we observe a systematic dependency of the nucleon excited-state masses
on source- and sink-smearing levels. To the best of our knowledge, this is the
first clear indication that a correlation matrix of standard nucleon
interpolators is insufficient to isolate the eigenstates of QCD.Comment: May 2009.13pp, Minor changes and references adde
Charmonium spectral functions in Nf=2 QCD
We report on a study of charmonium at high temperature in 2-flavour QCD. This
is the first such study with dynamical fermions. Using an improved anisotropic
lattice action, spectral functions are extracted from correlators in the vector
and pseudoscalar channels. No signs of medium-induced suppression of the ground
states are seen for temperatures up to 1.5T_c, while at T~2T_c there are clear
signs of modifications. The current systematic and statistical uncertainties in
our data, in particular the relatively coarse lattice and small volume, do not
allow us to draw a firm conclusion at this stage.Comment: 6 pages, talk by JIS at Lattice 2005 (Non-zero temperature and
density
Practical all-to-all propagators for lattice QCD
A new method for computing all elements of the lattice quark propagator is
proposed. The method combines the spectral decomposition of the propagator,
computing the lowest eigenmodes exactly, with noisy estimators which are
'diluted', i.e. taken to have support only on a subset of time, space, spin or
colour. We find that the errors are dramatically reduced compared to
traditional noisy estimator techniques.Comment: 24 pages, 18 figure
The effect of Camelina sativa cake diet supplementation on sensory and volatile profiles of ewe’s milk
The aim of this study was to evaluate the sensory profile based on the principal component analysis (PCA) and cluster analysis of Euclidean distances as well as evaluate a volatile profile in ewes’ milk. The analysis was conducted using SPME GC/TOFMS. Tested milk came from ewes fed concentrate supplemented with 10 and 20% Camelina sativa (L.) Crantz cake (CSC). This plant containing unsaturated fatty acids as well as natural antioxidants (for example, tocopherol), may constitute an excellent source of energy in the feed ratio for animals, at the same time improving the composition of fatty acids in milk fats. Milk of ewes fed CSC had a distinct animal, grainy and processed aroma. After pasteurization, the cooked and dairy fat aroma intensified. At the same time the overall dairy aroma, highly characteristic of the control milk, was considerably reduced. An addition of CSC to the diet of ewes resulted in an increase in the content of volatiles, primarily fatty acids. The applied milk pasteurization had a significant effect on a further increase in the contents of volatiles. First of all furans, furanones and furfural, being the Maillard reaction products, were accumulated.Key words: Sheep milk, sensory analysis, flavor analysis, volatiles in milk
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