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Relativistic exchange current corrections to neutrino--nucleus cross sections are presented assuming non--vanishing strange quark form factors for the constituent nucleons. For charged current processes the exchange current corrections can…

Nuclear Theory · Physics 2009-10-28 Y. Umino , J. M. Udias , P. J. Mulders

We analyze the non-perturbative structure of the strange sea of the nucleon within a meson cloud picture. In a low $Q^2$ approach in which the nucleon is viewed as a three valon bound state, we evaluate the probability distribution of an…

High Energy Physics - Phenomenology · Physics 2009-10-31 H. R. Christiansen , J. Magnin

We consider constraints on the momentum fraction of the $K$ and $K^*$ meson carried by the strange quark that follow from exact operator identities, similar to those for the divergence of the quark part of the QCD energy-momentum tensor.…

High Energy Physics - Phenomenology · Physics 2009-11-10 V. M. Braun , A. Lenz

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 strange contribution to the electric and magnetic form factors of the nucleon is determined at a range of discrete values of $Q^2$ up to $1.4$ GeV$^2$. This is done by combining recent lattice QCD results for the electromagnetic form…

High Energy Physics - Lattice · Physics 2015-03-05 P. E. Shanahan , R. Horsley , Y. Nakamura , D. Pleiter , P. E. L. Rakow , G. Schierholz , H. Stüben , A. W. Thomas , R. D. Young , J. M. Zanotti

We estimate the 3 \pi continuum contribution to the nucleon strange quark vector current form factors, including the effect of a 3 \pi <----> \rho \pi resonance. We find the magnitude of this OZI-violating contribution to be comparable to…

High Energy Physics - Phenomenology · Physics 2009-10-30 H. -W. Hammer , M. J. Ramsey-Musolf

Dispersion relations allow for a coherent description of the nucleon electromagnetic form factors measured over a large range of momentum transfer, $Q^2 \simeq 0 \ldots 35$ GeV$^2$. Including constraints from unitarity and perturbative QCD,…

High Energy Physics - Phenomenology · Physics 2008-11-26 P. Mergell , Ulf-G. Meißner , D. Drechsel

We perform a global analysis of all recent experimental data from elastic parity-violating electron scattering at low $Q^2$. The values of the electric and magnetic strange form factors of the nucleon are determined at $Q^2 = 0.1$ GeV/$c^2$…

Nuclear Experiment · Physics 2008-11-26 Jianglai Liu , Robert D. McKeown , Michael J. Ramsey-Musolf

We present a systematic study of the sensitivity of quasielastic neutrino-nucleus cross sections at intermediate energies to the strange quark sea of the nucleon. To this end, we investigate the impact of the weak strangeness form factors…

Nuclear Theory · Physics 2008-11-26 N. Jachowicz , P. Vancraeyveld , P. Lava , C. Praet , J. Ryckebusch

The strange form factors of the proton are basic to an understanding of proton structure, and are presently the focus of many experiments. Before the strangeness effects can be extracted from data, it is necessary to calculate and remove…

High Energy Physics - Phenomenology · Physics 2011-04-15 Randy Lewis , Nader Mobed

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

Selected topics in strangeness nuclear physics are critically reviewed. This includes production, structure and weak decay of $\Lambda$--Hypernuclei, the $\bar K$ nuclear interaction and the possible existence of $\bar K$ bound states in…

Nuclear Experiment · Physics 2012-05-17 Elena Botta , Tullio Bressani , Gianni Garbarino

We examine the presence of strangeness-bearing components, hyperons and kaons, in dense neutron star matter. Calculations are performed using relativistic mean field models, in which both the baryon-baryon and kaon-baryon interactions are…

Nuclear Theory · Physics 2009-09-25 R. Knorren , M. Prakash , P. J. Ellis

The strangeness degrees of freedom in the parton structure of the nucleon are explored in the global analysis framework, using the new CTEQ6.5 implementation of the general mass perturbative QCD formalism of Collins. We systematically…

High Energy Physics - Phenomenology · Physics 2014-11-18 H. L. Lai , P. Nadolsky , J. Pumplin , D. Stump , W. K. Tung , C. -P. Yuan

The recent Investigations in the chiral quark model show that kaon productions of nucleon play an important role in understanding the structure of baryons. The evidences of a third $S_{11}$ resonance in the second resonance region and two…

Nuclear Theory · Physics 2009-10-30 Zhenping Li

In this paper a discussion is made of the article by the HERMES Collaboration, Phys.Lett. B666,446, where several important results concerning strange quark properties in the nucleon were presented. By analysing the sum of K+-…

High Energy Physics - Experiment · Physics 2012-11-29 M. Stolarski

After the EMC and subsequent experiments at CERN, SLAC and DESY on the deep inelastic scattering of polarized leptons on polarized nucleons, it is now established that the Q^2=0 value of the axial strange form factor of the nucleon, a…

High Energy Physics - Phenomenology · Physics 2009-11-07 W. M. Alberico , S. M. Bilenky , C. Maieron

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…

I review recent studies of strangeness content in the nucleon pertaining to the flavor-singlet $g_A^0$, the $\bar{s}s$ matrix element and the strangeness electric and magnetic form factors $G_E^s(q^2)$ and $G_M^s(q^2)$, based on lattice QCD…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. F. Liu

The strange quark contribution to the vector and axial form factors of the nucleon has been determined for momentum transfers in the range $0.45<Q^2<1.0$ GeV$^2$. The results are obtained via a combined analysis of forward-scattering,…

High Energy Physics - Experiment · Physics 2008-11-26 S. F. Pate , D. W. McKee , V. Papavassiliou
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