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We determine the strange quark condensate from lattice QCD for the first time and compare its value to that of the light quark and chiral condensates. The results come from a direct calculation of the expectation value of the trace of the…

High Energy Physics - Lattice · Physics 2013-03-14 C. McNeile , A. Bazavov , C. T. H. Davies , R. J. Dowdall , K. Hornbostel , G. P. Lepage , H. D. Trottier

We present the strange electromagnetic form factors of the nucleon using lattice QCD simulations with degenerate light, a strange, and a charm quark in the sea with masses tuned to their physical values. For the first time, the strange…

We study the strangeness electromagnetic form factors of the nucleon from the N_f=2+1 clover fermion lattice QCD calculation. The disconnected insertions are evaluated using the Z(4) stochastic method, along with unbiased subtractions from…

High Energy Physics - Lattice · Physics 2010-11-05 Takumi Doi , Mridupawan Deka , Shao-Jing Dong , Terrence Draper , Keh-Fei Liu , Devdatta Mankame , Nilmani Mathur , Thomas Streuer

The scalar strange-quark matrix element of the nucleon is computed with lattice QCD. A mixed-action scheme is used with domain-wall valence fermions computed on the staggered MILC sea-quark configurations. The matrix element is determined…

High Energy Physics - Lattice · Physics 2013-06-26 Parikshit Junnarkar , Andre Walker-Loud

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

Lattice calculations of the mass of the strange quark are reviewed. In particular, the reason for the spread in values is explained with emphasis on the effects that recently implemented improvements have had on the lattice determinations.

High Energy Physics - Phenomenology · Physics 2007-05-23 Sinead Ryan

We present a calculation of the strangeness and charmness contents <N|\bar{s}s|N> and <N|\bar{c}c|N> of the nucleon from dynamical lattice QCD with 2+1 flavors. The calculation is performed with overlap valence quarks on 2+1-flavor…

High Energy Physics - Phenomenology · Physics 2013-08-20 M. Gong , A. Alexandru , Y. Chen , T. Doi , S. J. Dong , T. Draper , W. Freeman , M. Glatzmaier , A. Li , K. F. Liu , Z. Liu

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

We present a calculation of $< x >_s$ for the strange quark in the nucleon. We also report the ratio of the strange $< x >$ to that of $u/d$ in the disconnected insertion which will be useful in constraining the global fit of parton…

High Energy Physics - Lattice · Physics 2015-03-11 Mingyang Sun , Yi-Bo Yang , Keh-Fei Liu , Ming Gong

There are two mechanisms for the generation of an asymmetry between the strange and anti-strange quark distributions in the nucleon: nonperturbative contributions originating from nucleons fluctuating into virtual baryon-meson pairs such as…

High Energy Physics - Phenomenology · Physics 2015-06-05 Guan-Qiu Feng , Fu-Guang Cao , Xin-Heng Guo , A. I. Signal

In current lattice simulations of nucleon properties, the up and down quark masses are significantly larger than their physical values, while the strange quark can be included in simulations with its physical mass. When the up and down…

High Energy Physics - Lattice · Physics 2009-11-07 Jiunn-Wei Chen , Martin J. Savage

We determine the strange and light quark condensates in full lattice QCD for the first time. This is done by direct calculation of the expectation value of the trace of the quark propagator followed by subtraction of the appropriate…

High Energy Physics - Lattice · Physics 2013-01-31 C. T. H. Davies , C. McNeile , A. Bazavov , R. J. Dowdall , K. Hornbostel , G. P. Lepage , H. Trottier

This contribution summarizes a presentation combining two topics in lattice QCD. Firstly, the gluon propagator in Landau gauge is calculated in quenched QCD on a large (32^3x64) lattice at beta=6.0. New structure seen in the infrared region…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. G. Williams

The calculation of the nucleon strangeness form factors from N_f=2+1 clover fermion lattice QCD is presented. Disconnected insertions are evaluated using the Z(4) stochastic method, along with unbiased subtractions from the hopping…

High Energy Physics - Lattice · Physics 2015-05-20 Takumi Doi , Mridupawan Deka , Shao-Jing Dong , Terrence Draper , Keh-Fei Liu , Devdatta Mankame , Nilmani Mathur , Thomas Streuer

The precision reached by recent lattice QCD results allows for the first time to investigate whether the measured hadronic spectrum is missing some additional strange states, which are predicted by the Quark Model but have not yet been…

We present a calculation of the nucleon sigma term on two-flavor QCD configurations with dynamical overlap fermions. We analyse the lattice data for the nucleon mass using the baryon chiral perturbation theory. Using partially quenched data…

High Energy Physics - Lattice · Physics 2010-01-21 H. Ohki , H. Fukaya , S. Hashimoto , H. Matsufuru , J. Noaki , T. Onogi , E. Shintani , N. Yamada

The distributions of the quark number and chiral condensate over the gauge fields are computed for QCD in Euclidean space at nonzero quark chemical potential. As both operators are non-hermitian the distributions are in the complex plane.…

High Energy Physics - Lattice · Physics 2014-11-20 M. P. Lombardo , K. Splittorff , J. J. M. Verbaarschot

We calculate the strange magnetic moment of the nucleon on a quenched $16^3 \times 24$ lattice at $\beta = 6.0$, and with Wilson fermions at $\kappa$ = 0.148, 0.152, and 0.154. The strange quark contribution from the disconnected insertion…

High Energy Physics - Lattice · Physics 2009-10-31 Nilmani Mathur , Shao-Jing Dong

We report a lattice QCD calculation of the strange quark contribution to the nucleon's magnetic moment and charge radius. This analysis presents the first direct determination of strange electromagnetic form factors including at the…

High Energy Physics - Phenomenology · Physics 2017-01-30 Raza Sabbir Sufian , Yi-Bo Yang , Andrei Alexandru , Terrence Draper , Keh-Fei Liu , Jian Liang

We evaluate the light, strange and charm scalar content of the nucleon using one lattice QCD ensemble generated with two degenerate light quarks with mass fixed to their physical value. We use improved techniques to evaluate the…