Flavors Of Kogut-Susskind Quarks Research Articles

Phase Structure of QCD and Forces between Quark Clusters

Langevin simulations of finite temperature quantum chromodynamics with two flavors of Kogut-Susskind quarks on 83×4 lattice are presented. It is emphasized that the chiral phase transition strengthens as the quark mass mq, decreases towards zero, changing from a continuous crossover at mqα=0.2 to a first order transition at mqα=0.1. The critical coupling at mq=0 is estimated to be βc= 6/gc2=5.29−5.32, and the physical scale of Tc≃(0.19− 0.24)mρ. Deconfining phase transition takes place simultaneously with the chiral transition. Preliminary results for quark-antiquark potential derived from Polyakov line correlations are also presented.

Heavy-light decay constants with dynamical gauge configurations and wilson or improved valence quark actions

We describe a calculation of heavy-light decay constants including virtual quark loop effects. We have generated dynamical gauge configurations at three β values using two flavors of Kogut-Susskind quarks with a range of masses. These are analyzed with a Wilson valence quark action. Preliminary results based on a “fat-link” clover valence quark action are also reported. Results from the two methods differ by 30 to 50 MeV, which is presumably due to significant — but as yet unobserved — lattice spacing dependence in one or both of the approaches.

Phase structure of lattice QCD at finite temperature for 2+1 flavors of Kogut-Susskind quarks

We report on a study of the finite-temperature chiral transition on an N t = 4 lattice for 2 + 1 flavors of Kogut-Susskind quarks. We find the point of physical quark masses to lie in the region of crossover, in agreement with results of previous studies. Results of a detailed examination of the m u,d = m s case indicate vanishing of the screening mass of σ meson at the end point of the first-order transition.

MILC studies of high temperature QCD — a progress report

We summarize recently completed studies of the equation of state for QCD with two flavors of Kogut-Susskind quarks on lattices with six time slices, and of the high temperature crossover for two flavors of Wilson quarks with a Symanzik improved gauge action and the clover quark action. In addition, we give a progress report on extensions of the Kogut-Susskind calculations at N t = 4 to smaller masses in an effort to clarify the scaling behavior near the transition.

QCD thermodynamics at Nt = 8 and 12

We present results from studies of high temperature QCD with two flavors of Kogut-Susskind quarks on 16 3 × 8 lattices at a quark mass of am q = 0.00625 and on 24 3 × 12 lattices at quark masses am q = 0.008 and 0.016. The value of the crossover temperature is consistent with that obtained on coarser lattices and/or at larger quark masses. Results are presented for the chiral order parameter and for the baryon number susceptibility.

Pion decay constant in full lattice QCD

The pion decay constant is calculated for full QCD on the lattice employing a variety of methods derived from current algebra and PCAC relations. The calculation is made at β=5.7 on a 20 4 lattice with two flavors of Kogut-Susskind quarks. Most of the calculation is made in the Landau gauge, for which various methods give results in a very good agreement, yielding ƒ π=97±9 ( statistical) ± 4 ( systematic) MeV . In particular the results obtained with the gauge non-invariant axial-vector current perfectly agrees with those of the gauge invariant current, if corrected by the Z factor using the mean-field improvement of the gauge coupling constant and operators. Dependence of the results on the type of gauge fixing is also examined using the Coulomb gauge.

Quark structure of static correlators in high temperature QCD

We present results of numerical simulations of quantum chromodynamics at finite temperature with two flavors of Kogut-Susskind quarks on the Intel iPSC/860 parallel processor. We investigate the properties of the objects whose exchange gives static screening lengths by reconstructing their correlated quark-antiquark structure.

QCD thermodynamics with two flavors at Nt=6.

The first results of numerical simulations of quantum chromodynamics on the Intel iPSC/860 parallel processor are presented. We performed calculations with two flavors of Kogut-Susskind quarks at {ital N}{sub {ital t}}=6 with masses of 0.15{ital T} and 0.075{ital T} (0.025 and 0.0125 in lattice units) in order to locate the crossover from the low-temperature regime of ordinary hadronic matter to the high-temperature chirally symmetric regime. As with other recent two-flavor simulations, these calculations are insufficient to distinguish between a rapid crossover and a true phase transition. The phase transition is either absent or feeble at this quark mass. An improved estimate of the crossover temperature in physical units is given and results are presented for the hadronic screening lengths in both the high- and low-temperature regimes.

QCD thermodynamics with two flavors of quarks[1

We present results of numerical simulations of quantum chromodynamics at finite temperature on the Intel iPSC/860 parallel processor. We performed calculations with two flavors of Kogut-Susskind quarks and of Wilson quarks on 6 × 123 lattices in order to study the crossover from the low temperature hadronic regime to the high temperature regime. We investigate the properties of the objects whose exchange gives static screening lengths be reconstructing their correlated quark-antiquark structure.

Quantum chromodynamics at 6/g2=5.60.

We have carried out a simulation of quantum chromodynamics using the hybrid-molecular-dynamics algorithm with two flavors of Kogut-Susskind quarks. We have used Kogut-Susskind and Wilson valence quarks to calculate the hadron mass spectrum. Among our extensive results we discuss baryon hyperfine splitting, the nucleon-to-\ensuremath{\rho} mass ratio, the sclar-to-tensor-glueball mass ratio, and the quantization and susceptibility of the topological charge. We have used a gauge coupling of 6/${\mathit{g}}^{2}$=5.60, and quark masses ${\mathit{am}}_{\mathit{q}}$=0.025 and 0.01, in generating gauge configurations on ${12}^{4}$, ${12}^{3}$\ifmmode\times\else\texttimes\fi{}24, and ${16}^{4}$ lattices.

QCD thermodynamics with eight time slices

Preliminary simulations of lattice QCD with two flavors of Kogut-Susskind quarks with masses of $0.025{a}^{\ensuremath{-}1}$ and $0.0125{a}^{\ensuremath{-}1}$ locate the expected crossover from the low-temperature regime of ordinary hadronic matter to the high-temperature chiral-symmetric regime. These calculations are insufficient to distinguish between a rapid crossover and a true phase transition.