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Related papers: Nucleon isovector scalar charge from overlap fermi…

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We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally)…

High Energy Physics - Lattice · Physics 2015-10-27 T. Chiarappa , K. Jansen , K. -I. Nagai , M. Papinutto , L. Scorzato , A. Shindler , C. Urbach , U. Wenger , I. Wetzorke

We report on our calculation of the nucleon axial charge gA in QCD with two flavours of dynamical quarks. A detailed investigation of systematic errors is performed, with a particular focus on contributions from excited states to…

High Energy Physics - Lattice · Physics 2013-09-26 S. Capitani , M. Della Morte , G. von Hippel , B. Jäger , A. Jüttner , B. Knippschild , H. B. Meyer , H. Wittig

We evaluate the isovector nucleon electromagnetic form factors in quenched and full QCD on the lattice using Wilson fermions. In the quenched theory we use a lattice of spatial size 3 fm at beta=6.0 enabling us to reach low momentum…

High Energy Physics - Lattice · Physics 2008-11-26 C. Alexandrou , G. Koutsou , J. W. Negele , A. Tsapalis

We report isovector form factors and low moments of isovector structure functions of nucleon from the coarse RIKEN-BNL-Columbia (RBC) and UKQCD joint dynamical (2+1)-flavor domain-wall fermions (DWF) ensembles. The lattice cut off is…

High Energy Physics - Lattice · Physics 2008-10-02 Shigemi Ohta , Takeshi Yamazaki

The long-range, parity-odd nucleon interaction generated by single pion exchange is captured in the parity-odd pion-nucleon coupling $h^1_\pi$. Its calculation in lattice QCD requires the evaluation of 4-quark operator nucleon 3-point…

High Energy Physics - Lattice · Physics 2023-11-30 Marcus Petschlies , Nikolas Schlage , Aniket Sen , Carsten Urbach

We present an update of our determination of the isovector charges $g_A^{u-d}$, $g_S^{u-d}$ and $g_T^{u-d}$, and the isovector twist-2 forward matrix elements $\langle x\rangle_{u-d}$, $\langle x\rangle_{\Delta u-\Delta d}$ and $\langle…

High Energy Physics - Lattice · Physics 2024-02-06 Dalibor Djukanovic , Georg von Hippel , Harvey B. Meyer , Konstantin Ottnad , Hartmut Wittig

We determine the nucleon-sigma terms from lattice QCD. We find that the dominant excited state contamination in the nucleon three-point function with a scalar current is due to the transition between the nucleon and a S-wave scattering…

High Energy Physics - Lattice · Physics 2025-01-30 Lorenzo Barca , Gunnar Bali , Sara Collins

We present a quenched lattice QCD calculation of the first few moments of the polarized and un-polarized structure functions of the nucleon. Our calculations are done using domain wall fermions and the DBW2 gauge action with inverse lattice…

High Energy Physics - Lattice · Physics 2011-08-11 Kostas Orginos , Thomas Blum , Shigemi Ohta

We present a lattice-QCD based analysis of the nucleon sigma terms using gauge ensembles with $N_f = 2 + 1$ flavors of ${\cal O}(a)$-improved Wilson fermions, with a complete error budget concerning excited-state contaminations, the chiral…

High Energy Physics - Lattice · Physics 2024-01-17 Andria Agadjanov , Dalibor Djukanovic , Georg von Hippel , Harvey B. Meyer , Konstantin Ottnad , Hartmut Wittig

We present a quenched lattice calculation of the nucleon isovector vector and axial-vector charges gV and gA. The chiral symmetry of domain wall fermions makes the calculation of the nucleon axial charge particularly easy since the…

High Energy Physics - Lattice · Physics 2019-08-15 Shoichi Sasaki , Kostas Orginos , Shigemi Ohta , Tom Blum

We determine the light baryon spectrum on ensembles generated by the Coordinated Lattice Simulations (CLS) effort, employing $N_f=2+1$ flavours of non-perturbatively improved Wilson fermions. The hadron masses are interpolated and…

We present the isovector axial, induced pseudoscalar, and pseudoscalar form factors of the nucleon using three twisted-mass fermion ensembles with degenerate up- and down-, strange-, and charm-quarks with masses tuned to their physical…

We present a short summary for the calculations of the nucleon $\textit{isovector}$ form factors, which are relevant to improving the accuracy of the current neutrino oscillation experiments. The calculations are carried out with two of…

We present a lattice QCD calculation of the pion scalar form factor and associated radii with fully controlled systematics. Lattice results are computed on a large set of 17 gauge ensembles with $N_f=2+1$ Wilson Clover-improved sea quarks.…

High Energy Physics - Lattice · Physics 2025-03-27 Konstantin Ottnad , Georg von Hippel

The current status is reported of joint lattice numerical calculations by LHP and RBC collaborations of isovector nucleon form factors using 2+1-flavor physical-mass domain-wall fermions ensemble at a lattice cutoff $a^{-1}$ of 1.730(4) GeV…

High Energy Physics - Lattice · Physics 2021-11-29 Shigemi Ohta

I will review heavy baryon chiral perturbation theory for the nucleon delta degrees of freedom and then examine the recent dynamical lattice calculations of the nucleon mass from the BMW, ETM, JLQCD, LHP, MILC, NPLQCD, PACS-CS, QCDSF/UKQCD…

High Energy Physics - Lattice · Physics 2009-12-04 Andre Walker-Loud

Analyses on possible systematics in some isovector nucleon observables in the RBC+UKQCD 2+1-flavor dynamical domain-wall fermion (DWF) lattice-QCD are presented. The vector charge, axial charge, quark momentum and helicity fractions, and…

High Energy Physics - Lattice · Physics 2014-10-31 Shigemi Ohta

We determine the strong-isospin violating component of the neutron-proton mass difference from fully-dynamical lattice QCD and partially-quenched QCD calculations of the nucleon mass, constrained by partially-quenched chiral perturbation…

High Energy Physics - Lattice · Physics 2008-11-26 Silas R. Beane , Kostas Orginos , Martin J. Savage

Strange quark content of the nucleon is calculated in dynamical lattice QCD employing the overlap fermion formulation. For this quantity, exact chiral symmetry guaranteed by the Ginsparg-Wilson relation is crucial to avoid large…

High Energy Physics - Lattice · Physics 2011-06-21 JLQCD collaboration , K. Takeda , S. Aoki , S. Hashimoto , T. Kaneko , J. Noaki , T. Onogi

We determine generalized form factors of the nucleon from lattice simulations with $N_f = 2$ mass-degenerate non-perturbatively improved Wilson-Sheikholeslami-Wohlert fermions down to a pion mass of 150 MeV. We also present the resulting…

High Energy Physics - Lattice · Physics 2016-01-20 Gunnar Bali , Sara Collins , Meinulf Göckeler , Rudolf Rödl , Andreas Schäfer , Andre Sternbeck