257 research outputs found
Update on the hadron spectrum with two flavors of staggered quarks
We present an update on the MILC Collaboration's light hadron spectrum
calculation with two flavors of dynamical, staggered quarks. We present
extrapolations of the nucleon to rho mass ratio to the continuum limit for
fixed values of the pi to rho mass ratio including the physical one.Comment: 3 pages, LaTex with espcrc2 and epsf, 5 postscript figures included,
Lattice '97 Proceeding
Light hadron spectrum---MILC results with the Kogut-Susskind and Wilson actions
We present the current status of our ongoing calculations of the light hadron
spectrum with both Kogut-Susskind (KS) and Wilson quarks in the valence or
quenched approximation. We discuss KS quarks first and find that the chiral
extrapolation is potentially the biggest source of systematic error. For the
Wilson case, we focus on finite volume and source size effects at 6/g^2=5.7. We
find no evidence to support the claim that there is a finite volume effect
between N_s=16 and 24 of approximately 5%.Comment: 11 pages, 11 figures, LaTeX, uses espcrs2, epsf, Invited talk
presented by S. Gottlieb at Lattice QCD on Parallel Computers, University of
Tsukuba, March, 1997, to appear in the proceeding
Lattice results for the decay constant of heavy-light vector mesons
We compute the leptonic decay constants of heavy-light vector mesons in the
quenched approximation. The reliability of lattice computations for heavy
quarks is checked by comparing the ratio of vector to pseudoscalar decay
constant with the prediction of Heavy Quark Effective Theory in the limit of
infinitely heavy quark mass. Good agreement is found. We then calculate the
decay constant ratio for B mesons: .
We also quote quenched MeV.Comment: 11 pages, 3 postscript figs., revtex; two references adde
Glueballs and Hybrids (Gluons as Constituents)
After a brief introduction to hybrid and glueball source operators, I
summarize recent lattice results for these particles.Comment: 5 pages, contribution to LATTICE-99, corrected glueball mass tabl
Recent MILC spectrum results
We report on results from three spectrum calculations with staggered quarks:
1) a quenched calculation with the standard action for the gluons and quarks;
2) a quenched calculation with improved actions for both the gluons and quarks;
and 3) a calculation with two flavors of dynamical quarks using the standard
actions for the gluons and quarks.Comment: Poster presented at LATTICE96(spectrum);4 pages of LaTeX, uses
espcrc2 and epsf, six postscript figures include
Study of new systems concepts for a Titan atmospheric probe
Results of a systems concepts study for a Titan Probe were examined. The key tradeoffs performed are described in detail. Mass breakdown of each Probe subsystem or major element were given. The mission analysis performed to determine compliance with the high altitude sampling and descent time requirements are described. The baseline Descent Module design was derived. The element of the Probe System left on the Carrier after separation were described
Heavy-light decay constants---MILC results with the Wilson action
We present the current status of our ongoing calculations of pseudoscalar
meson decay constants for mesons that contain one light and one heavy quark
(f_B, f_{B_s}, f_D, f_{D_s}). We are currently generating new gauge
configurations that include dynamical quarks and calculating the decay
constants. In addition, we have several new results for the static
approximation. Those results, as well as several refinements to the analysis,
are new since Lattice '96. Our current (still preliminary) value for f_B is 156
+- 11 +- 30 +- 14 MeV, where the first error is from statistical and fitting
errors, the second error is an estimate of other systematic errors within the
quenched approximation and the third error is an estimate of the quenching
error. For the ratio f_{B_s}/f_B, we get 1.11 +- 0.02 +- 0.03 +- 0.07.Comment: 8 pages, 9 figures, LaTeX, uses espcrs2, epsf, Invited talk presented
by S. Gottlieb at Lattice QCD on Parallel Computers, University of Tsukuba,
March, 1997, to appear in the proceeding
Finite Temperature Lattice QCD with Clover Fermions
We report on our simulation of finite temperature lattice QCD with two
flavors of Symanzik-improved fermions and
Symanzik-improved glue. Our thermodynamic simulations were performed on an lattice, and we have performed complementary zero temperature
simulations on an lattice. We compare our results to those from
simulations with two flavors of Wilson fermions and discuss the improvement
resulting from use of the improved action.Comment: 3 pages, 4 figures, Talk presented at Lattice 9
Exotic hybrid mesons with light quarks
Hybrid mesons, made from a quark, an antiquark and gluons, can have quantum
numbers inaccessible to conventional quark-antiquark states. Confirmation of
such states would give information on the role of "dynamical" color in low
energy QCD. We present preliminary results for hybrid meson masses using light
Wilson valence quarks.Comment: 4 pages, 4 figures, Talk presented at LATTICE96(spectrum
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