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Related papers: Nucleon charges with dynamical overlap fermions

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We calculate the pion vector and scalar form factors in two-flavor QCD. Gauge configurations are generated with dynamical overlap quarks on a 16^3 x 32 lattice at a lattice spacing of 0.12 fm with sea quark masses down to a sixth of the…

High Energy Physics - Lattice · Physics 2012-08-27 JLQCD , TWQCD collaborations , : , T. Kaneko , S. Aoki , T. W. Chiu , H. Fukaya , S. Hashimoto , T. H. Hsieh , H. Matsufuru , J. Noaki , T. Onogi , E. Shintani , N. Yamada

Using a reweighting technique combined with a low-mode truncation of the fermionic determinant, we estimate the quark-mass dependence of the QCD topological susceptibility with overlap fermions. In contrast to previous lattice simulations…

High Energy Physics - Lattice · Physics 2009-09-25 Tamas G. Kovacs

The domain wall fermion (DWF) method, with its almost perfectly preserved chiral symmetry on the lattice, makes the calculation of the nucleon axial charge particularly easy. By maintaining chiral symmetry and using the Ward-Takahashi (WT)…

High Energy Physics - Lattice · Physics 2009-11-07 Shigemi Ohta

We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (Nf=2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark…

We present the first lattice-QCD calculation of the unpolarized strange and charm parton distribution functions using large-momentum effective theory (LaMET). We use a lattice ensemble with 2+1+1 flavors of highly improved staggered quarks…

High Energy Physics - Lattice · Physics 2021-12-01 Rui Zhang , Huey-Wen Lin , Boram Yoon

We show that the interplay of chiral effective field theory and lattice QCD can be used in the evaluation of so-called disconnected diagrams, which appear in the study of the isoscalar and isovector channels of pion-pion scattering and have…

High Energy Physics - Lattice · Physics 2017-12-22 Neramballi Ripunjay Acharya , Feng-Kun Guo , Ulf-G. Meißner , Chien-Yeah Seng

In these proceedings we address the computation of quark-line disconnected diagrams in lattice QCD. The evaluation of these diagrams is required for many phenomenologically interesting observables, but suffers from large statistical errors…

High Energy Physics - Lattice · Physics 2020-01-27 Leonardo Giusti , Tim Harris , Alessandro Nada , Stefan Schaefer

We present results of lattice computations using overlap fermions on a twisted mass background. $N_f=2$ full QCD gauge configurations have been produced by the ETM Collaboration with very light pions (down to less than 300 MeV), with small…

High Energy Physics - Lattice · Physics 2009-04-14 Nicolas Garron , Luigi Scorzato

The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as…

We study the nucleon axial charge in the chiral perturbation theory for a mixed lattice action of Ginsparg-Wilson valence quarks and staggered sea quarks. In particular, we investigate the lattice spacing $a^2$-dependence of the neutron to…

High Energy Physics - Lattice · Physics 2007-05-23 Fu-Jiun Jiang

We perform numerical simulations of lattice QCD with two flavors of dynamical overlap quarks, which have exact chiral symmetry on the lattice. While this fermion discretization is computationally demanding, we demonstrate the feasibility to…

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

Protons and neutrons have a rich structure in terms of their constituents, the quarks and gluons. Understanding this structure requires solving Quantum Chromodynamics (QCD). However QCD is extremely complicated, so we must numerically solve…

High Energy Physics - Lattice · Physics 2019-08-14 D. B. Renner , R. G. Edwards , G. Fleming , Ph. Hagler , J. W. Negele , K. Orginos , A. V. Pochinsky , D. G. Richards , W. Schroers

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…

High Energy Physics - Lattice · Physics 2008-11-26 JLQCD collaboration , H. Fukaya , S. Hashimoto , K. Kanaya , T. Kaneko , H. Matsufuru , K. Ogawa , M. Okamoto , T. Onogi , N. Yamada

We determine the quark contributions to the nucleon spin Delta s, Delta u and Delta d as well as their contributions to the nucleon mass, the sigma-terms. This is done by computing both, the quark line connected and disconnected…

We show the first lattice QCD results on the axial charge $g_A^{N^*N^*}$ of $N^*(1535)$ and $N^*(1650)$. The measurements are performed with two flavors of dynamical quarks employing the renormalization-group improved gauge action at…

High Energy Physics - Lattice · Physics 2008-11-26 Toru T. Takahashi , Teiji Kunihiro

We calculate both connected and disconnected contribution to the $\pi$-$N$ $\sigma$-term in quenched lattice QCD with Wilson quark action on a $12^3\times 20$ lattice at $\beta=5.7$. The latter is evaluated with the aid of the variant wall…

High Energy Physics - Lattice · Physics 2009-10-22 M. Fukugita , Y. Kuramashi , M. Okawa , A. Ukawa

We calculate the "strange quark content of the nucleon", <N| s s_bar |N>, which is important for interpreting the results of some dark matter detection experiments. The method is to evaluate quark-line disconnected correlations on the MILC…

High Energy Physics - Lattice · Physics 2011-03-18 D. Toussaint , W. Freeman

We present a determination, from lattice QCD, of charge symmetry violation in the spin- independent and spin-dependent parton distribution functions of the nucleon. This is done by chirally extrapolating recent QCDSF/UKQCD Collaboration…

Nuclear Theory · Physics 2013-08-09 P. E. Shanahan , A. W. Thomas , R. D. Young

We present results for the isoscalar electromagnetic form factors of the nucleon computed on the Coordinated Lattice Simulations (CLS) ensembles with $N_\mathrm{f} = 2 + 1$ flavors of $\mathcal{O}(a)$-improved Wilson fermions and an…

High Energy Physics - Lattice · Physics 2022-09-21 Dalibor Djukanovic , Georg von Hippel , Harvey B. Meyer , Konstantin Ottnad , Miguel Salg , Jonas Wilhelm , Hartmut Wittig
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