相关论文: Further Improvements to Staggered Quarks
We resolve contradictions in the literature concerning the origins and size of unphysical flavor-changing strong interactions generated by the staggered-quark discretization of QCD. We show that the leading contributions are tree-level in…
We present results from a systematic perturbative investigation of taste-changing in improved staggered quarks. We show one-loop taste-changing interactions can be removed perturbatively by an effective four-quark term and calculate the…
We compare several improved actions for staggered quarks. We study the effect of improvement on the taste changing interactions by calculating the splitting in the pion spectrum. We investigate the effect of the improvement on some…
We investigate a class of actions for lattice QCD with staggered quarks aimed at reducing the flavour symmetry violations associated with using staggered fermions. These actions replace the gauge field link fields in the quark action with…
We use perturbative Symanzik improvement to create a new staggered-quark action (HISQ) that has greatly reduced one-loop taste-exchange errors, no tree-level order a^2 errors, and no tree-level order (am)^4 errors to leading order in the…
We report on a study of QCD thermodynamics with three flavors of quarks, using a Symanzik improved gauge action and the Asqtad O(a^2) improved staggered quark action. Simulations were carried out with lattice spacings 1/4T, 1/6T and 1/8T…
We present preliminary results from exploring the phase diagram of finite temperature QCD with three degenerate flavors and with two light flavors and the mass of the third held approximately at the strange quark mass. We use an order…
We present preliminary results from exploring the phase diagram of finite temperature QCD with three degenerate flavors and with two light flavors and the mass of the third held approximately at the strange quark mass. We use an order…
Improved staggered quark actions are designed to suppress flavour changing strong interactions. We discuss the perturbation theory for this type of actions and show the improvements to reduce the quark mass renormalisation compared to naive…
We introduce a new class of actions for staggered quarks in lattice QCD which significantly reduce flavour symmetry violations in the pion mass spectrum. An action introduced by the MILC collaboration for the same purpose is seen to be a…
We present an update of our study of high temperature QCD with three flavors of quarks, using a Symanzik improved gauge action and the Asqtad staggered quark action. Simulations are being carried out on lattices with Nt=4, 6 and 8 for the…
Taste symmetry violations in staggered fermion formulations correlate strongly with the cut-off (lattice spacing) dependence in thermodynamic quantities. Better taste symmetry on the lattice can be achieved either by decreasing the lattice…
As one test of the validity of the staggered-fermion fourth-root determinant trick, we examine the suppression of the topological susceptibility of the QCD vacuum in the limit of small quark mass. The suppression is sensitive to the number…
We report on progress in our study of high temperature QCD with three flavors of improved staggered quarks. Simulations are being carried out with three degenerate quarks with masses less than or equal to the strange quark mass, $m_s$, and…
We describe recent progress on generation of gauge configurations using the Highly Improved Staggered Quark (HISQ) action that was designed by the HPQCD/UKQCD collaboration. The HISQ action requires two levels of smearing with a…
The scaling corrections that affected previous staggered calculations of B_K have been proved to be reduced by using improved actions (HYP, Asqtad) in the quenched approximation. This improved behaviour allows us to perform a reliable…
We have calculated the step scaling function and the running coupling of QCD in the Schroedinger functional scheme with four flavors of O(a) improved Wilson quarks. Comparisons of our non-perturbative results with 2-loop and 3-loop…
We calculate the kaon B-parameter, B_K, to next-to-leading order in staggered chiral perturbation theory. We find expressions for partially quenched QCD with three sea quarks, quenched QCD, and full QCD with m_u = m_d but not equal to m_s.…
Growing evidence indicates that in the continuum limit the rooted staggered action is in the correct QCD universality class, the non-local terms arising from taste breaking can be viewed as lattice artifacts. In this paper we consider the…
Dramatic progress has been made over the last decade in the numerical study of quantum chromodynamics (QCD) through the use of improved formulations of QCD on the lattice (improved actions), the development of new algorithms and the rapid…