相关论文: Scaling of FLIC Fermions
We review the long term project of the ALPHA collaboration to compute in QCD the running coupling constant and quark masses at high energy scales in terms of low energy hadronic quantities. The adapted techniques required to numerically…
This paper presents a formulation of lattice fermions applicable to all quark masses, large and small. We incorporate interactions from previous light-fermion and heavy-fermion methods, and thus ensure a smooth connection to these limiting…
We report the current status of the on-going lattice-QCD calculations of nucleon isovector axial charge, g_A, using the RBC/UKQCD 2+1-flavor dynamical domain-wall fermion ensembles at lattice cutoff of about a^{-1}=1.4 GeV in a spatial…
We non-perturbatively calculate the renormalization factor of the static axial vector current in O(a) improved quenched lattice QCD. Its scale dependence is mapped out in the Schroedinger functional scheme by means of a recursive…
Lattice QCD with staggered quarks is augmented by the addition of a chiral 4-fermion interaction. The Dirac operator is now non-singular at $m_q=0$, decreasing the computing requirements for light quark simulations by at least an order of…
We show at the example of the matrix element between pion states of a twist-2, non-singlet operator that Wilson twisted mass fermions allow to compute this phenomenologically relevant quantitiy at small pseudo scalar masses of O(270 MeV).…
We present an update on our on-going project to compute hadronic observables for Nf=2 flavours of O(a) improved Wilson fermions at small lattice spacings. The procedure to determine the lattice scale via the mass of the Omega baryon is…
We study the locality and topological properties of fat link clover overlap (FCO) actions. We find that a small amount of fattening (2-4 steps of APE or 1 step of HYP) already results in greatly improved properties compared to the Wilson…
We calculate the chiral condensate of QCD with 2, 2+1 and 3 flavors of sea quarks. Lattice QCD simulations are performed employing dynamical overlap fermions with up and down quark masses covering a range between 3 and 100 MeV. On L ~…
As a direct source of information on chiral symmetry breaking within QCD, the sigma commutator is of considerable importance. With recent advances in the calculation of hadron masses within full QCD it is of interest to see whether the…
The mass of the $1^{-+}$ exotic meson, created with hybrid interpolating fields, is explored at light quark masses approaching 25 MeV ($m_\pi / m_\rho \simeq 1/3$). Access to such light quark masses is facilitated by the use of the Fat-Link…
We provide first evidence that Matrix Models describe the low lying complex Dirac eigenvalues in a theory with dynamical fermions at non-zero density. Lattice data for gauge group SU(2) with staggered fermions are compared to detailed…
We present a study of the flavor symmetry breaking in the pion spectrum for various improved staggered fermion actions. To study the effects of link fattening and tadpole improvement, we use three different variants of the p4 action -…
We propose a strategy for conducting lattice QCD simulations at fixed volume but variable quark mass so as to investigate the physical effects of dynamical fermions. We present details of techniques which enable this to be carried out…
We calculate numerically universal finite-size-scaling functions of the magnetization for the three-dimensional O(4) and O(2) spin models. The approach of these functions to the infinite-volume scaling functions is studied in detail on the…
We continue our simulations of lattice QCD at finite quark-number chemical potential, $\mu$, using the complex-Langevin equation (CLE) with gauge-cooling and adaptive updating. The CLE is used because QCD at finite finite $\mu$ has a…
We use a space-time asymmetric O(a) improved fermion action and fix the asymmetry non-perturbatively to restore the relativistic dispersion relation. We compute spectra and matrix elements of quarkonia and heavy-light mesons and compare…
We study the mass spectra and various mass differences of heavy hadrons containing one or more bottom quarks using MILC's $N_f = 2+1+1$ HISQ gauge ensembles at three lattice spacings. For the valence quarks, we employ a combination of…
We discuss how to formulate Dirac fermion operator on a finite lattice such that it can provide a nonperturbative regularization for massless fermion interacting with a background gauge field.
In the Hamiltonian picture, free spin-$1/2$ Dirac fermions on a bipartite lattice have an $O(4)$ (spin-charge) symmetry. Here we construct an interacting lattice model with an interaction $V$, which is similar to the Hubbard interaction but…