相关论文: Strange quark momentum fraction from overlap fermi…
In current lattice simulations of nucleon properties, the up and down quark masses are significantly larger than their physical values, while the strange quark can be included in simulations with its physical mass. When the up and down…
We present results of a quenched QCD simulation with overlap fermions on a lattice of volume V = 16^3X32 at beta=6.0, which corresponds approximatively to a lattice cutoff of 2 GeV and an extension of 1.4 fm. From the two-point correlation…
We introduce a stochastic sandwich method with low-mode substitution to evaluate the connected three-point functions. The isovector matrix elements of the nucleon for the axial-vector coupling $g_A^3$, scalar couplings $g_S^3$ and the quark…
FLIC overlap fermions are a variant of the standard (Wilson) overlap action, with the FLIC (Fat Link Irrelevant Clover) action as the overlap kernel rather than the Wilson action. The structure of the FLIC overlap fermion propagator in…
We calculate connected and disconnected contributions to the flavour singlet scalar density amplitude of the nucleon in a full QCD lattice simulation with $n_f=2$ dynamical Wilson fermions at $\beta=5.6$ on a $16^3 \times 32$ lattice. We…
We report on a measurement of the parity violating asymmetry in the elastic scattering of polarized electrons off unpolarized protons with the A4 apparatus at MAMI in Mainz at a four momentum transfer value of $Q^2$ = \Qsquare (GeV/c)$^2$…
We present results for the strangeness contribution to the nucleon, <N|ss|N>, and to the spin of the nucleon, Delta s. By combining several variance reduction techniques for all-to-all propagators we are able to obtain gains in terms of…
We present numerical simulation of QCD with two dynamical quark flavors described by the overlap fermion action on a $16^3\times 32\times (0.12 {\rm fm})^4$ lattice. We calculate pseudo-scalar masses and decay constants and investigate…
Disconnected diagrams give crucial contributions to the physics of flavor singlet hadrons and to scalar form factors of non-singlet hadrons. Naive lattice calculation of the disconnected diagrams, however, requires a huge number of fermion…
A completely non-perturbative estimate is given for the u/d and strange quark masses in quenched QCD using O(a) improved fermions and, for comparison, Wilson fermions. For improved fermions we find m_{u/d}^MSbar(\mu=2 GeV) = 4.4(2) MeV,…
The nucleon strange and anti-strange distribution asymmetry is an important issue in the study of the nucleon structure. In this work, we show that the heavy quark recombination processes from a perturbative QCD picture can give a sizable…
The strange form factors of nucleon are studied with the nonlocal chiral effective Lagrangian. One loop contributions from both octet and decuplet intermediate states are included. The relativistic regulator is obtained by the nonlocal…
In a recent study of the Lambda(1405), the suppression of the strange-quark contribution to the magnetic form factor was interpreted as the discovery of a dominant antikaon-nucleon composition for this low-lying state. We confirm this…
We report on the two-flavor QCD simulation in the epsilon-regime using the overlap fermion formulation. Sea quark mass is reduced to ~ 2 MeV on a 16^3x32 lattice with the lattice spacing ~ 0.11fm. Topological charge is fixed at Q=0. We…
We evaluate the light, strange and charm scalar content of the nucleon using one lattice QCD ensemble generated with two degenerate light quarks with mass fixed to their physical value. We use improved techniques to evaluate the…
Majorana fermions are rising as a promising key component in quantum computation. While the prevalent approach is to use a quadratic (i.e. non-interacting) Majorana Hamiltonian, when expressed in terms of Dirac fermions, generically the…
We compute the one-loop self-energy correction to the massive domain wall quark propagator. Combining this calculation with simulations at several gauge couplings, we estimate the strange quark mass in the continuum limit. The perturbative…
We study the quenched chiral behavior of hadrons with the pseudoscalar mass as low as $\approx 280$ MeV. We look for quenched chiral logs in the pion mass, determine the renormalized quark mass, and observe quenched artifacts in the $a_0$…
A detailed study of nucleon parton distribution functions is performed within a radiative Next-to-Next-to Leading Order (NNLO) parton model whose low-scale input is rigidly described by wave functions which include quarks and dressing…
We present a determination of the strange quark mass for two flavours (nf=2) of light dynamical quarks using the axial Ward identity. The calculations are performed on the lattice using O(a) improved Wilson fermions and include a fully…