Related papers: The pion-nucleon sigma term from lattice QCD
We consider multi-particle contributions to nucleon two- and three-point functions from the perspective of chiral dynamics. Lattice nucleon interpolating operators, which have definite chiral transformation properties, can be mapped into…
Previous extrapolations of lattice QCD results for the nucleon mass to the physically relevant region of small quark masses, using chiral effective field theory, are extended and expanded in several directions. A detailed error analysis is…
We study the sigma term and the strange quark content of nucleon in 2+1-flavor QCD with dynamical overlap fermions. We analyze the lattice data of nucleon mass taken at two different strange quark masses with five values of up and down…
A calculational scheme for obtaining the electric polarizability of the neutron in lattice QCD with dynamical quarks is developed, using the background field approach. The scheme differs substantially from methods previously used in the…
We calculate mesonic two-point functions in the epsilon-regime of two-flavor QCD on the lattice with exact chiral symmetry. We use gauge configurations of size 16^3 32 at the lattice spacing a \sim 0.11 fm generated with dynamical overlap…
We present 2+1 flavor Lattice QCD calculations of the nucleon scalar and tensor charges. Using the BMW clover-improved Wilson action with pion masses between 150 and 350 MeV and three source-sink separations between 0.9 and 1.4 fm, we…
We present a calculation using lattice QCD of the ratios of decay constants of the excited states of the pion, to that of the pion ground state, at three values of the pion mass between 400 and 700 MeV, using an anisotropic clover fermion…
The energies of the excited states of the Nucleon, Delta and Omega are computed in lattice QCD, using two light quarks and one strange quark on anisotropic lattices. The calculations are performed at three values of the pion mass: 392(4),…
We present preliminary results for the axial, scalar and tensor charges of the nucleon measured in 2+1 flavor QCD with the physical light quarks ($m_\pi=135$ MeV). Our simulations are carried out with gauge configurations generated by the…
The current status of some nucleon isovector observables, the vector charge, \(g_V\), axial charge, \(g_A\), quark momentum fraction, \(\langle x \rangle_{u-d}\), and quark helicity fraction, \(\langle x \rangle_{\Delta u - \Delta d}\),…
We study the coupled pion-nucleon system (negative parity, isospin 1/2) based on a lattice QCD simulation for nf=2 mass degenerate light quarks. Both, standard 3-quarks baryon operators as well as meson-baryon (4+1)-quark operators are…
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 scalar strangeness content of the nucleon, characterized by the so-called strangeness-nucleon sigma term, is of fundamental importance in understanding its sea-quark flavor structure. We report a determination of the octet baryon sigma…
The nucleon axial form factors -- axial $G_A$, induced pseudoscalar $\widetilde{G}_P$ and pseudoscalar $G_P$ -- have displayed large systematics in lattice QCD calculations. The major symptoms were the violation of the partially conserved…
We present a lattice QCD study of the puzzling positive-parity nucleon channel, where the Roper resonance $N^*(1440)$ resides in experiment. The study is based on an ensemble of gauge configurations with $N_f=2+1$ Wilson-clover fermions…
pi-N and pi-pi interactions near threshold are uniquely sensitive to the chiral symmetry breaking part of the strong interaction. The pi-N sigma-term value with its implications for nucleon quark structure and the recent controversy…
We calculate the strange quark content of the nucleon in 2+1-flavor lattice QCD. Chirally symmetric overlap fermion formulation is used to avoid the contamination from up and down quark contents due to an operator mixing between strange and…
High statistics results for the isovector momentum fraction, $\langle x \rangle_{u-d}$, helicity moment, $\langle x \rangle_{\Delta u-\Delta d}$, and the transversity moment, $\langle x\rangle_{\delta u-\delta d}$, of the nucleon are…
As a direct source of information on chiral symmetry breaking within QCD, the sigma commutator is of considerable importance. Since hadron structure is a non-perturbative problem, numerical calculations on a space-time lattice are currently…
We present a realistic lattice QCD study on low-energy $N$-$J/\psi$ and $N$-$\eta_c$ interactions based on (2+1) flavor configurations with nearly physical pion mass $m_\pi=146$ MeV. The interactions, extracted from the spacetime…