Related papers: Baryon Axial Charge in a Finite Volume
We determine the nucleon axial, scalar and tensor charges and the nucleon $\sigma$-terms using twisted mass fermions. We employ three ensembles with approximately equal physical volume of about 5.5~fm, three values of the lattice spacing,…
An analysis is presented of the ground state baryon's (N and \Delta) masses and axial couplings in the combined 1/Nc and chiral expansions. Renormalization and alternative power counting schemes are discussed to one loop (NNLO). An…
The comparison of chiral perturbation theory formulae with data from lattice QCD simulations is discussed. Observables in the pion sector as well as in the baryon sector are considered, including the nucleon mass in a finite volume.
We report on recent work about the study of quark mass dependence of nucleon magnetic moments and axial-vector coupling constant. We examine the feasibility of chiral effective field theory methods for the extrapolation of lattice QCD data…
The current status of calculations of simple nucleon structure observables is reviewed, with a focus on the axial charge. A major challenge is the combination of an exponentially decaying signal-to-noise ratio and the need for large…
The iso-vector axial-vector form factors of the \Delta-\Delta transition are calculated in the framework of the Light-cone QCD sum rules method. Also, axial charge of \Delta baryon is predicted.
Now that Lattice QCD calculations are beginning to include QED, it is important to better understand how hadronic properties are modified by finite-volume QED effects. They are known to exhibit power-law scaling with volume, in contrast to…
The nucleon axial charge is a central ingredient in nuclear and particle physics, and a key observable in precision tests of the electroweak Standard Model sector and beyond. We report on the first complete calculation of its electroweak…
The baryon axial vector current is computed in heavy baryon chiral perturbation theory in the large-$N_c$ limit, where $N_c$ is the number of color charges. One-loop nonanalytic corrections of order $m_q \ln m_q$ are comprised in the…
I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of…
We calculate the spin-averaged amplitude for doubly virtual forward Compton scattering off nucleons in the framework of manifestly Lorentz invariant baryon chiral perturbation theory at complete one-loop order $O(p^4)$. The calculations are…
We report on a lattice QCD calculation of the nucleon axial charge, $g_A$, using M\"{o}bius Domain-Wall fermions solved on the dynamical $N_f=2+1+1$ HISQ ensembles after they are smeared using the gradient-flow algorithm. The calculation is…
We calculate the magnetic dipole moment of the Delta baryon using a background magnetic field on 2+1-flavors of clover fermions on anisotropic lattices. We focus on the finite volume effects that can be significant in background field…
We report on a recent study of finite-volume effects on the lowest-lying octet baryon masses using the covariant baryon chiral perturbation theory up to next-to-leading order by analysing the latest $n_f = 2 + 1$ lattice QCD results from…
We present the first calculation on the $\Delta$ axial-vector and pseudoscalar form factors using lattice QCD. Two Goldberger-Treiman relations are derived and examined. A combined chiral fit is performed to the nucleon axial charge, N to…
A matrix Hamiltonian model is developed to address the finite-volume effects appearing in studies of baryon resonances in lattice QCD. The Hamiltonian model includes interaction terms in a transparent way, and can be readily generalized to…
Lattice simulations of QCD have produced precise estimates for the masses of the lowest-lying hadrons which show excellent agreement with experiment. By contrast, lattice results for the vector and axial vector form factors of the nucleon…
The nucleon axial form factor is a dominant contribution to errors in neutrino oscillation studies. Lattice QCD calculations can help control theory errors by providing first-principles information on nucleon form factors. In these…
We present a lattice QCD calculation of the $\Delta(1232)$ matrix elements of the axial-vector and pseudoscalar currents. The decomposition of these matrix elements into the appropriate Lorentz invariant form factors is carried out and the…
We summarize developments concerning the quark mass dependence of nucleon magnetic moments and the axial-vector coupling constant g_A. The aim is to explore the feasibility of chiral effective field theory methods for the extrapolation of…