Related papers: Quark structure from the lattice Operator Product …
We report preliminary results of our ongoing lattice computation of the Landau gauge quark propagator and the soft gluon limit of the quark-gluon vertex with 2 flavors of dynamical O(a) improved Wilson fermions.
This review focuses on the discussion of three key results of nucleon structure calculations on the lattice. These three results are the quark contribution to the nucleon spin, J_q, the nucleon-Delta transition form factors, and the nucleon…
We present a numerical lattice quantum chromodynamics calculation of isovector form factors and the first few moments of the isovector structure functions of the nucleon. The calculation employs two degenerate dynamical flavors of…
By employing a twisted mass term, we compare recent results from lattice calculations of Nf=2 dynamical Wilson fermions with Wilson Chiral Perturbation Theory (WChPT). The final goal is to determine some combinations of Gasser-Leutwyler Low…
We show how the leading physical and Wilson low-energy constants associated with Wilson fermions in lattice gauge theory can be determined individually by using spectral information of the Wilson Dirac operator with fixed index at finite…
We investigate the low-lying eigenvalues of the improved Wilson-Dirac operator in the Schroedinger functional with two dynamical quark flavors. At a lattice spacing of approximately 0.1 fm we find more very small eigenvalues than in the…
In a recent article Hasenfratz and von Allmen have suggested a fixed point action for two flavors of Weyl fermions on the lattice with gauge group SU(2). The block-spin transformation they use maps the chiral and vector symmetries of the…
We report on new results of the spin dependent structure functions $g_1$ and $h_1$ of the nucleon. An attempt is made to convert the moments, which is what one computes on the lattice, to quark distribution functions.
It has been suggested to use the production of Lambda hyperons for investigating the nucleon spin structure. The viability of this idea depends crucially on the spin structure of the Lambda. Using nonperturbatively O(a) improved Wilson…
Quark line disconnected matrix elements of an operator, such as the axial current, are difficult to compute on the lattice. The standard method uses a stochastic estimator of the operator, which is generally very noisy. We discuss and…
It is suggested that the fermion determinant for a vector-like gauge theory with strictly massless quarks can be represented on the lattice as $\det{{1+V}\over 2}$, where $V=X(X^\dagger X)^{-1/2}$ and $X$ is the Wilson-Dirac lattice…
Recent progress in lattice QCD calculations of nucleon structure will be presented. Calculations of nucleon matrix elements and form factors have long been difficult to reconcile with experiment, but with advances in both methodology and…
We make several observations concerning the low quark mass region with Wilson fermions and how this is connected with the epsilon regime in the continuum. A transition from tiny cutoff effects to rather large discretization errors would…
The problem of unphysical zero modes in lattice QCD with Wilson fermions can be solved in a clean way by including a mass term proportional to $i \psibar \gamma_5 \tau^3 \psi$ in the standard lattice theory with Nf=2 mass degenerate Wilson…
We give a brief sketch of lattice structure function calculations and review previous results for the axial coupling $g_A$. We outline a new technique for treating fermions on the lattice that preserves chiral symmetry, domain wall…
We present here the latest results from the QCDSF collaboration for (moments of) structure functions and generalized form factors in full QCD with Nf=2 O(a)-improved Wilson fermions based on simulations closer to the chiral and continuum…
We discuss results from lattice calculations for a few observables that are sensitive to different length scales in the high temperature phase of QCD and can give insight into its non-perturbative structure. We compare lattice results with…
We compare the behavior of different lattice Dirac operators in gauge backgrounds which are lattice discretizations of a classical instanton. In particular we analyze the standard Wilson operator, a chirally improved Dirac operator and the…
We report scale setting and hadronic properties for our new lattice QCD gauge configuration set (HAL-conf-2023). We employ $(2+1)$-flavor nonperturbatively improved Wilson fermions with stout smearing and the Iwasaki gauge action on a…
The feasibility of using lattice chiral fermions which are free of $O(a)$ errors for both the heavy and light quarks is examined. The fact that the effective quark propagators in these fermions have the same form as that in the continuum…