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Related papers: Strange quark contribution to nucleon form factors

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We calculate the nucleon strange quark content directly from disconnected three-point functions. Numerical simulations are carried out in two-flavor QCD using the overlap quark action with up and down quark masses down to a fifth of the…

High Energy Physics - Lattice · Physics 2010-11-05 JLQCD collaboration , K. Takeda , S. Aoki , S. Hashimoto , T. Kaneko , T. Onogi , N. Yamada

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…

High Energy Physics - Lattice · Physics 2016-01-29 Jeremy Green

The strange magnetic form factor of the nucleon is studied in the heavy baryon chiral effective approach at next to leading order. The one loop contributions from kaon and intermediate octet and decuplet hyperons are included, using…

High Energy Physics - Phenomenology · Physics 2015-06-18 P. Wang , D. B. Leinweber , A. W. Thomas

We investigate scalar matrix elements of the nucleon using $N_f=2+1+1$ flavors of maximally twisted mass fermions at a fixed value of the lattice spacing of $a\approx 0.078{\rm fm}$. We compute disconnected contributions to the relevant…

High Energy Physics - Lattice · Physics 2012-02-17 S. Dinter , V. Drach , K. Jansen

We report a new determination of the strange quark contribution to the proton's magnetic form factor at a four-momentum transfer Q2 = 0.1 (GeV/c)^2 from parity-violating e-p elastic scattering. The result uses a revised analysis of data…

Nuclear Experiment · Physics 2009-07-09 SAMPLE collaboration , D. T. Spayde

Quenched lattice QCD simulations and quenched chiral perturbation theory are used together for this study of strangeness in the nucleon. Dependences of the matrix elements on strange quark mass, valence quark mass and momentum transfer are…

High Energy Physics - Phenomenology · Physics 2009-11-07 Randy Lewis , W. Wilcox , R. M. Woloshyn

It is imperative that lattice QCD serve to develop our understanding of hadron structure and, where possible, to guide the interpretation of experimental data. There is now a great deal of effort directed at the calculation of the…

High Energy Physics - Lattice · Physics 2010-02-17 J. D. Ashley , D. B. Leinweber , A. W. Thomas , R. D. Young

The strange quark scalar content plays an important role in both the description of nucleon structure and in the determination of dark matter direct detection cross sections. As a measure of the strange-quark contribution to the nucleon…

High Energy Physics - Lattice · Physics 2013-01-10 R. D. Young

Using heavy baryon chiral perturbation theory to one loop, we derive an analytic and parameter-free expression for the momentum dependence of the strange magnetic form factor of the nucleon $G_M^{(s)} (Q^2)$ and its corresponding radius.…

High Energy Physics - Phenomenology · Physics 2009-10-31 T. R. Hemmert , Ulf-G. Meißner , S. Steininger

We report in the present talk recent results of the tensor properties of the nucleon within the framework of the chiral quark-soliton model. The tensor and anomalous tensor magnetic form factors are calculated for the momentum transfer up…

High Energy Physics - Phenomenology · Physics 2015-05-27 Tim Ledwig , Antonio Silva , Hyun-Chul Kim

The strange-quark vector current $\rho$-to-$\pi$ meson transition form factor is computed at one-loop order using strange meson intermediate states. A comparison is made with a $\phi$-meson dominance model estimate. We find that one-loop…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. L. Goity , M. J. Musolf

A few chosen nucleon properties are described from a lattice QCD perspective: the nucleon sigma term and the scalar strangeness in the nucleon; the vector form factors in the nucleon, including the vector strangeness contribution, as well…

High Energy Physics - Lattice · Physics 2015-05-28 Harvey B. Meyer

We present results on the scalar strangeness and charm contents of the nucleon and of the disconnected contributions to the nucleon spin. These are obtained on two flavour non-perturbatively improved Sheikholeslami-Wilson configurations at…

High Energy Physics - Lattice · Physics 2010-11-05 Gunnar Bali , Sara Collins , Andreas Schaefer

We present results from the QCDSF/UKQCD collaboration for hyperon electromagnetic form factors and axial charges obtained from simulations using Nf=2+1 flavours of O(a)-improved Wilson fermions. We also consider matrix elements relevant for…

High Energy Physics - Lattice · Physics 2013-11-21 A. N. Cooke , R. Horsley , Y. Nakamura , D. Pleiter , P. E. L. Rakow , P. Shanahan , G. Schierholz , H. Stüben , J. M. Zanotti

The chiral constituent quark model ($\chi$CQM) has been extended to calculate the flavor structure of the nucleon through the meson-nucleon sigma terms which have large contributions from the quark sea and are greatly affected by chiral…

High Energy Physics - Phenomenology · Physics 2015-05-28 Harleen Dahiya , Neetika Sharma

A synopsis exemplifying the employment of Dyson-Schwinger equations in the calculation and explanation of hadron electromagnetic form factors and related phenomena. In particular the contribution: presents the pion form factor computed…

Nuclear Theory · Physics 2009-02-19 I. C. Cloet , C. D. Roberts

There are several different experimental indications, such as the strangeness contribution to the magnetic moment of the proton, sigma_{\pi N} term, strange spin polarization, ratio of strange and non strange quark flavor distributions…

High Energy Physics - Phenomenology · Physics 2008-11-26 Harleen Dahiya , Manmohan Gupta

Strange matrix elements of the nucleon are calculated within the light-cone formulation of the meson cloud model. The $Q^2$ dependence of the strange vector and axial vector form factors is computed, and the strangeness radius and magnetic…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. Melnitchouk , M. Malheiro

We present results for the nucleon electromagnetic form factors, including the momentum transfer dependence and derived quantities (charge radii and magnetic moment). The analysis is performed using O(a) improved Wilson fermions in Nf=2 QCD…

High Energy Physics - Lattice · Physics 2015-09-30 S. Capitani , M. Della Morte , D. Djukanovic , G. von Hippel , J. Hua , B. Jäger , B. Knippschild , H. B. Meyer , T. D. Rae , H. Wittig

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…

High Energy Physics - Lattice · Physics 2009-01-09 H. Ohki , H. Fukaya , S. Hashimoto , T. Kaneko , H. Matsufuru , J. Noaki , T. Onogi , E. Shintani , N. Yamada , for JLQCD Collaboration
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