40514876
Hadronic correlation functions in the QCD plasma phase.
We present results for static hadronic correlation functions in the high-temperature phase of QCD with four flavors of dynamical quarks. We confirm chiral-symmetry restoration through the degeneracies of the spectrum of screening lengths. We also find that the screening lengths for the {rho} and {ital N} channels at {ital T}{approx gt}1.2{ital T}{sub {ital c}} are close to that in a free quark gas.
17443615
Lattice QCD for RHIC
I briefly introduce the methods by which lattice QCD predictions for RHIC are obtained. Next I deal with lattice determinations of strangeness production and event-to-event fluctuations of conserved quantities. I also present a new diagrammatic method for computing derivatives with respect to chemical potentials, and conclude with discussions of some tests of thermal perturbation theory which follow.
119431013
A precise determination of T_c in QCD from scaling
Existing lattice data on the QCD phase transition are analyzed in renormalized perturbation theory. In quenched QCD it is found that T_c scales for lattices with only 3 time slices, and that T_c/Lambda_msbar=1.15 \pm 0.05. A preliminary estimate in QCD with two flavours of dynamical quarks shows that this ratio depends on the quark mass. For realistic quark masses we estimate T_c/Lambda_msbar=0.49 \pm 0.02. We also investigate the equation of state in quenched QCD at 1-loop order in renormalised perturbation theory.
123004962
Flavour degrees of freedom and the transition temperature in QCD
We study the finite temperature transition in QCD with four flavours of dynamical quarks. Our simulation is performed on an 8×16 3 lattice for quarks of mass ma=0.01. At the coupling β c =5.15, we find long-lived metastable states, as well as an abrupt change in the entropy density, suggesting a first order phase transition. Using presently available results from corresponding calculations of the hadron masses and the chiral condensate, this gives us a transition temperature T c ≅100 MeV, which is a factor two lower than the transition temperature found in quenched QCD.
121387686
Hybrid Monte Carlo simulations of a two-dimensional gauge theory
Through a study of the dynamics of the two-dimensional U(1) pure gauge theory we find exponential slowing down in barrier penetration problems. We verify that the dynamical critical exponent in HMC can be tuned exactly to 1, and that normal and gauge fixed updates have equal cost.
122166973
The phase diagram of QCD: methods and logic of the comparison of experiments and theory
Abstract A small review of the phase diagram of QCD is presented. This is followed by a discussion of the conditions under which experimental data on the fluctuations of conserved quantities in heavy-ion collisions can be treated in the grand canonical ensemble. A robust method for detecting the presence of a nearby critical point in experiments is given. There is a short discussion of the need for non-Gaussian error analysis.
10011120
Bc spectroscopy in a quantum-chromodynamic potential model.
We have investigated {ital B}{sub {ital c}} spectroscopy with the use of a quantum-chromodynamic potential model which was recently used by us for the light-heavy quarkonia. We give our predictions for the energy levels and the {ital E}1 transition widths. We also find, rather surprisingly, that although {ital B}{sub {ital c}} is not a light-heavy system, the heavy quark effective theory with the inclusion of the {ital m}{sub {ital b}}{sup -}{sup 1} and {ital m}{sub {ital b}}{sup -}{sup 1}ln{ital m}{sub {ital b}} corrections is as successful for {ital B}{sub {ital c}} as it is for {ital B} and {ital B}{sub {ital s}}. {copyright} {ital 1995 The American Physical Society.}
32229676
Precision description of the octet-baryon magnetic moments.
Addition of an SU(3) (flavor)-tensor term having isoscalar and isovector parts to the quark-model expressions reduces the chi/sup 2/ per degree of freedom to 1.28 from 80 for the recent precision magnetic-moment data of the octet baryons. The isospin symmetry is well obeyed as the ratio of the magnetic moment of the down quark to that of the up quark is -0.499.
10313486
Semirelativistic potential model for charmonium.
9625384
Clear evidence of redundant operators in Monte Carlo studies of the Ising model.
After reviewing the notion of redundant operators and the procedure for deriving them analytically for Ising systems, we present Monte Carlo renormalization-group data that clearly show their occurrence as eigenoperators in d = 2.
12480798
Critical behavior of the two-dimensional XY model.
We present detailed Monte Carlo results for the susceptibility {chi}, correlation length {xi}, and specific heat {ital C}{sub {ital v}} for the {ital XY} model. The simulations are done on 64{sup 2}, 128{sup 2}, 256{sup 2}, and 512{sup 2} lattices over the temperature range 0.98{le}{ital T}{le}1.43 corresponding to 2{lt}{xi}{lt}70. Fits to {chi} and {xi} data favor a Kosterlitz-Thouless (KT) singularity over a second-order transition; however, unconstrained four-parameter KT fits do not confirm the predicted values {nu}=0.5 and {eta}=0.25. Our best estimate, {ital T}{sub {ital c}}=0.894(5), is obtained using KT fits with {nu} fixed at 0.5. The exponent {eta} is calculated as a function of temperature in the spin-wave phase using Monte Carlo renormalization-group and finite-size-scaling methods. Both methods give consistent results and we find {eta}{approx}0.235 at {ital T}=0.894. We also present results for the behavior of vortex density across the transition and exhibit how the dilute-gas approximation breaks down.