31 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
A comparison of analysis techniques for extracting resonance parameters from lattice Monte Carlo data
Different methods for extracting resonance parameters from Euclidean lattice
field theory are tested. Monte Carlo simulations of the O(4) non-linear sigma
model are used to generate energy spectra in a range of different volumes both
below and above the inelastic threshold. The applicability of the analysis
methods in the elastic region is compared. Problems which arise in the
inelastic region are also emphasised.Comment: 17 pages, 20 figures; clarification and minor corrections added, to
appear in PR
Isoscalar meson spectroscopy from lattice QCD
We extract to high statistical precision an excited spectrum of
single-particle isoscalar mesons using lattice QCD, including states of high
spin and, for the first time, light exotic JPC isoscalars. The use of a novel
quark field construction has enabled us to overcome the long-standing challenge
of efficiently including quark-annihilation contributions. Hidden-flavor mixing
angles are extracted and while most states are found to be close to ideally
flavor mixed, there are examples of large mixing in the pseudoscalar and axial
sectors in line with experiment. The exotic JPC isoscalar states appear at a
mass scale comparable to the exotic isovector states.Comment: 4 pages, 4 figure
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
Dynamical QCD simulations on anisotropic lattices
The simulation of QCD on dynamical (Nf - 2) anisotropic lattices is described. A method for nonperturbative renormalisation of the parameters in the anisotropic gauge and quark actions is presented. The precision with which this tuning can be carried out is determined in dynamical simulations on 8³ X 48
and 8³ X 80 lattices