相关论文: New Developments in Lattice QCD: Calculation of Fl…
Flavour singlet contributions to the nucleon spin are elusive due to the fact that they cannot be determined directly in experiment but require extrapolations to the small x region. Direct calculations of these contributions are possible…
We report on our recent study of flavor singlet matrix elements calculated with the wall source method without gauge fixing. Results are presented for the mass difference between $\eta^{\prime}$ and pseudoscalar octet mesons, the $\pi$-N…
Method of calculating hadron multi-point functions and disconnected quark loop contributions which are not readily accessible through conventional techniques is proposed. Results are reported for pion-pion, pion-nucleon and nucleon-nucleon…
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…
I present a review of the current status and the most recent achievements in lattice QCD calculations of hadron structure. First, I overview the status and systematic uncertainties of nucleon structure "benchmark" quantities that are well…
We present recent developments in lattice QCD simulations as applied in the study of hadron structure. We discuss the challenges and perspectives in the evaluation of benchmark quantities such as the nucleon axial charge and the isovector…
Flavor singlet combinations of quark operators ${\cal{O}}_S^{\Gamma} = \bar{u}\Gamma u + \bar{d}\Gamma d + \bar{s}\Gamma s$ contribute to many important physical observables in the low energy region of QCD. Experimentally one finds the…
Recent progress in hadron structure calculations within lattice QCD is reviewed. Results on key observables such as the axial charge, the quark momentum fraction and the spin content of the nucleon are discussed with focus on open issues.…
The strangeness of the nucleon, <N|ss|N> - <0|ss|0>, is a quantity of interest for interpreting the results of dark matter detection experiments as well as for exploring the structure of the nucleon itself. We present a calculation of this…
Progress in the calculation of the electromagnetic properties of baryon excitations in lattice QCD is presenting new challenges in the determination of sea-quark loop contributions to matrix elements. A reliable estimation of the sea-quark…
This is a review of recent developments in hadron structure within the framework of Lattice QCD. The main focus is on recent achievements in the evaluation of nucleon quantities, such as the axial charge, electromagnetic form factors, the…
We calculate the nucleon sigma term in two-flavor lattice QCD utilizing the Feynman-Hellman theorem. Both sea and valence quarks are described by the overlap fermion formulation, which preserves exact chiral and flavor symmetries on the…
We show that hadronic matrix elements can be extracted from lattice simulations with background fields that arise from operator exponentiation. Importantly, flavour-singlet matrix elements can be evaluated without requiring the computation…
This document is one of a series of whitepapers from the USQCD collaboration. Here, we discuss opportunities for lattice QCD in neutrino-oscillation physics, which inevitably entails nucleon and nuclear structure. In addition to discussing…
Recent progress in Lattice QCD is highlighted. After a brief introduction to the methodology of lattice computations the presentation focuses on three main topics: Hadron Spectroscopy, Hadron Structure and Lattice Flavor Physics. In each…
We review recent progress on lattice calculations of nucleon spin structure, including the parton distribution functions, form factors, generalization parton distributions, and recent developments in lattice techniques.
As algorithms and computing power have advanced, lattice QCD has become a precision technique for many QCD observables. However, the calculation of nucleon matrix elements remains an open challenge. I summarize the status of the lattice…
An exploratory study is made of the nucleon-nucleon $s$-wave scattering lengths in quenched lattice QCD with the Wilson quark action. The $\pi$-$N$ and $\pi$-$\pi$ scattering lengths are also calculated for comparison. The calculations are…
Precise lattice QCD results for hadronic matrix elements, decay constants and form factors play a crucial role in the determination of CKM matrix elements and in the identification of possible new physics contributions to flavour violating…
I review the status of lattice-QCD calculations relevant to quark flavor physics. The recent availability of physical-mass ensembles with large physical volumes generated by a growing number of lattice collaborations is an exciting…