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Related papers: Strange quark contribution to nucleon form factors

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We discuss the calculation of disconnected diagrams needed for determining the strange quark content of the nucleon on the lattice. We present results for the strange scalar form factor and the related parameter f_Ts, which enters into the…

High Energy Physics - Lattice · Physics 2009-01-30 Ronald Babich , Richard Brower , Michael Clark , George Fleming , James Osborn , Claudio Rebbi

We discuss techniques for evaluating sea quark contributions to hadronic form factors on the lattice and apply these to an exploratory calculation of the strange electromagnetic, axial, and scalar form factors of the nucleon. We employ the…

High Energy Physics - Lattice · Physics 2012-05-23 Ronald Babich , Richard C. Brower , Michael A. Clark , George T. Fleming , James C. Osborn , Claudio Rebbi , David Schaich

We report on our calculation of the strange contribution to the vector and axial vector form factors. The strange charge radii, magnetic moment, and axial charge are extracted by model independent $z$-expansion fits to the $Q^2$-dependence…

High Energy Physics - Lattice · Physics 2019-11-05 Dalibor Djukanovic , Harvey Meyer , Konstantin Ottnad , Georg von Hippel , Jonas Wilhelm , Hartmut Wittig

We present results for the strange contribution to the electromagnetic form factors of the nucleon computed on the CLS ensembles with $N_f=2+1$ flavors of $\mathcal{O}(a)$-improved Wilson fermions and an $\mathcal{O}(a)$-improved vector…

High Energy Physics - Lattice · Physics 2019-12-10 Dalibor Djukanovic , Konstantin Ottnad , Jonas Wilhelm , Hartmut Wittig

We present preliminary results for strangeness form factors of the nucleon computed on the CLS ensembles with $N_f=2+1$ flavors of O($a$)-improved Wilson fermions. Our calculations are performed at two values of the lattice spacing ($a \in…

High Energy Physics - Lattice · Physics 2018-10-26 Dalibor Djukanovic , Harvey Meyer , Konstantin Ottnad , Georg von Hippel , Jonas Wilhelm , Hartmut Wittig

We evaluate the strange nucleon electromagnetic form factors using an ensemble of gauge configurations generated with two degenerate maximally twisted mass clover-improved fermions with mass tuned to approximately reproduce the physical…

High Energy Physics - Lattice · Physics 2018-05-23 C. Alexandrou , M. Constantinou , K. Hadjiyiannakou , K. Jansen , C. Kallidonis , G. Koutsou , A. Vaquero Aviles-Casco

We present results on the isovector and isoscalar nucleon axial form factors including disconnected contributions,using an ensemble of $N_f =2$ twisted mass clover- improved Wilson fermions simulated with approximately the physical value of…

The strange form factors of the nucleon are studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. A comparison with the available experimental world data from the SAMPLE, PVA4, HAPPEX…

Nuclear Theory · Physics 2008-11-26 R. Bijker

We apply the perturbative chiral quark model at one loop to calculate the strange form factors of the nucleon. A detailed numerical analysis of the strange magnetic moments and radii of the nucleon, and also the momentum dependence of the…

High Energy Physics - Phenomenology · Physics 2009-11-07 V. E. Lyubovitskij , P. Wang , Th. Gutsche , Amand Faessler

We present results on the nucleon axial and induced pseudo-scalar form factors using an ensemble of two degenerate twisted mass clover-improved fermions generated at the physical value of the pion mass. We evaluate the isovector and the…

The singlet axial form factor of the nucleon provides essential input for a complete understanding of the nucleon axial structure. Together with the isovector and isoscalar octet channels, in the forward limit it forms the basis for a full…

High Energy Physics - Lattice · Physics 2026-05-08 Alessandro Barone , Dalibor Djukanovic , Georg von Hippel , Harvey B. Meyer , Konstantin Ottnad , Hartmut Wittig

Quark line disconnected matrix elements of an operator, such as the axial current, are difficult to compute on the lattice. The standard method uses a stochastic estimator of the operator, which is generally very noisy. We discuss and…

High Energy Physics - Lattice · Physics 2019-01-16 R. Horsley , Y. Nakamura , H. Perlt , D. Pleiter , P. E. L. Rakow , G. Schierholz , A. Schiller , H. Stüben , R. D. Young , J. M. Zanotti

Contributions of strange quarks to the mass and spin of the nucleon, characterized by the observables f_Ts and Delta s, respectively, are investigated within lattice QCD. The calculation employs a 2+1-flavor mixed-action lattice scheme,…

High Energy Physics - Lattice · Physics 2013-05-30 M. Engelhardt

The total contribution of strange quarks to the intrinsic spin of the nucleon can be determined from a measurement of the strange-quark contribution to the nucleon's elastic axial form factor. We have studied the strangeness contribution to…

High Energy Physics - Experiment · Physics 2014-05-19 S. F. Pate , J. P. Schaub , D. P. Trujillo

We review the state of our knowledge concerning the contribution of strange quarks to various nucleon properties. In the case of the electric and magnetic form factors, the level of agreement between theory and experiment is very…

Nuclear Theory · Physics 2022-03-02 A. W. Thomas , P. E. Shanahan , 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

The electromagnetic form factors provide important insight into the internal structure of the nucleon and continue to be of major interest for experiment and phenomenology. For an intermediate range of momenta the form factors can be…

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 review a recent theoretical determination of the strange quark content of the electromagnetic form factors of the nucleon. These are compared with a global analysis of current experimental measurements in parity-violating electron…

Nuclear Theory · Physics 2008-11-26 Ross D. Young

The strangeness contribution to the electric and magnetic properties of the nucleon has been under investigation experimentally for many years. Lattice Quantum Chromodynamics (LQCD) gives theoretical predictions of these measurements by…

High Energy Physics - Lattice · Physics 2008-01-24 Dean Darnell
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