212 research outputs found
Decay Constants of Heavy-Light Mesons
The decay constants of the heavy-light pseudoscalar mesons are studied in a
high statistics run using the Wilson action at and , and
the clover action at . The systematics of discretisation
errors are discussed. Our best estimates of the decay constants are: =
218(9) MeV, = 1.11(1) and we obtain preliminary values for .Comment: at the Dallas Lattice Conference, October 1993. 3 pages in a single
postscript file, uuencoded form. Rome Preprint 93/98
apeNEXT: A multi-TFlops Computer for Simulations in Lattice Gauge Theory
We present the APE (Array Processor Experiment) project for the development
of dedicated parallel computers for numerical simulations in lattice gauge
theories. While APEmille is a production machine in today's physics simulations
at various sites in Europe, a new machine, apeNEXT, is currently being
developed to provide multi-Tflops computing performance. Like previous APE
machines, the new supercomputer is largely custom designed and specifically
optimized for simulations of Lattice QCD.Comment: Poster at the XXIII Physics in Collisions Conference (PIC03),
Zeuthen, Germany, June 2003, 3 pages, Latex. PSN FRAP15. Replaced for adding
forgotten autho
Quenched -parameter with the Wilson and Clover actions at
We present results for the Kaon parameter from a sample of
configurations using the Wilson action and configurations using the
Clover action, on a lattice at . A slight
improvement of the chiral behaviour of is observed due to the Clover
action. We have also compared the results for obtained from two different
procedures for the boosting of the coupling constant . We observe a strong
dependence of on the prescription adopted for in the Wilson case,
contrary to the results of the Clover case which are almost unaffected by the
choice of . Combining some recently obtained non perturbative estimates for
the renormalisation constants with our Clover matrix element, we observe a
significant improvement in the chiral behaviour of .Comment: 3 pages, Latex, Postscript file with figures available at
ftp://hpteo.roma1.infn.it/pub/preprints/lat94/donini ; to appear in Lattice
'94, Nucl. Phys. (Proc.Suppl.
Modern Electronic Techniques Applied to Physics and Engineering
Contains reports on two research projects
Non-perturbatively Improved Heavy-Light Mesons: Masses and Decay Constants
We present a study of the heavy-light spectrum and of the D- and B-meson
decay constants. The results wer e obtained in the quenched approximation, by
using the non-perturbatively improved Clover lattice action at beta=6.2, with a
sample of 100 configurations, on a 24^3 x 64 lattice. After a careful analysis
of th e systematic errors present in the extraction of the physical results, by
assuming quite conservative discretization errors, we find f_Ds=231 +/-
12^{+6}_{-1} MeV, f_D = 211 +/- 14^{+0}_{-12} MeV, f_Ds/f_D=1.10(2), f_Bs = 204
+/- 16^{+28}_{-0} MeV, f_B = 179 +/- 18^{+26}_{-9} MeV,
f_Bs/f_B=1.14(3)^{+0}_{-1}. Our results, which have smaller discretization
errors than many previous estimates at fixed value of the lattice spacing ,
support a large value of f_B in the quenched approximation.Comment: 26 pages, 9 Postscript figure
Modern Electronic Techniques Applied to Physics and Engineering
Contains reports on three research projects
A lattice study of the exclusive decay amplitude, using the Clover action at
We present the results of a numerical calculation of the
form factors. The results have been obtained by studying the relevant
correlation functions at , on an lattice, using the
-improved fermion action, in the quenched approximation. From the
study of the matrix element we have
obtained the form factor which controls the exclusive decay rate. The
results are compared with the recent results from CLEO. We also discuss the
compatibility between the scaling laws predicted by the Heavy Quark Effective
Theory (HQET) and pole dominance, by studying the mass- and -dependence of
the form factors. From our analysis, it appears that the form factors follow a
mass behaviour compatible with the predictions of the HQET and that the
-dependence of is weaker than would be predicted by pole dominance.Comment: 17 pages, LaTeX + epsf.sty. Uuencoded, compressed, tar archive
including the text and one postscript figur
A High Statistics Lattice Calculation of at Using the Clover Action
We present a calculation of in the static limit, obtained by numerical
simulation of quenched QCD, at on a lattice, using
the SW-Clover quark action. The decay constant has been extracted by studying
heavy(static)-light correlation functions of different smeared operators, on a
sample of 220 gauge field configurations. We have obtained MeV, where the first error comes from the uncertainty in the
determination of the matrix element and the second comes from the uncertainty
in the lattice spacing. We also obtain MeV and
. A comparison of our results with other
calculations of the same quantity is made.Comment: 12 pages, LaTex, 3 figs. (figures not included; available upon
request from [email protected]) ROME prep. 94/981, 18 February 199
- …