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: $f_{B^*}/f_B= 1.01(0.01)(^{+0.04}_{-0.01})$. We also quote quenched $f_{B^*}=177(6)(17)$ 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 ${\cal O}(a)$ Symanzik-improved fermions and ${\cal O}(a^2)$ Symanzik-improved glue. Our thermodynamic simulations were performed on an $8^3 \times 4$ lattice, and we have performed complementary zero temperature simulations on an $8^3 \times 16$ 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