# Nucleon Structure and Hyperon Form Factors from Lattice QCD.

## Abstract

In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point. to be 1.23(5), consistent with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton ismore »

- Authors:

- Publication Date:

- Research Org.:
- Brookhaven National Lab. (BNL), Upton, NY (United States)

- Sponsoring Org.:
- Doe - Office Of Science

- OSTI Identifier:
- 924428

- Report Number(s):
- BNL-79822-2008-CP

R&D Project: 81128; KB-02-01; TRN: US0802256

- DOE Contract Number:
- DE-AC02-98CH10886

- Resource Type:
- Conference

- Resource Relation:
- Conference: 11th International Baryons Conference; Seoul National University, Seoul, Korea; 20070611 through 20070615

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BARYONS; COUPLING CONSTANTS; EXTRAPOLATION; FERMIONS; FOCUSING; FORECASTING; FORM FACTORS; HYPERONS; MAGNETIC MOMENTS; MATRIX ELEMENTS; NUCLEONS; PIONS; PROTONS; QUANTUM CHROMODYNAMICS; QUARKS; RENORMALIZATION; STRANGENESS; STRUCTURE FUNCTIONS; SYMMETRY; VALENCE

### Citation Formats

```
Lin, H W.
```*Nucleon Structure and Hyperon Form Factors from Lattice QCD.*. United States: N. p., 2007.
Web.

```
Lin, H W.
```*Nucleon Structure and Hyperon Form Factors from Lattice QCD.*. United States.

```
Lin, H W. Mon .
"Nucleon Structure and Hyperon Form Factors from Lattice QCD.". United States. https://www.osti.gov/servlets/purl/924428.
```

```
@article{osti_924428,
```

title = {Nucleon Structure and Hyperon Form Factors from Lattice QCD.},

author = {Lin, H W},

abstractNote = {In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point. to be 1.23(5), consistent with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is found to be -0.066(2G), consistent with the Adelaide-JLab Collaboration's result. The hyperon {Sigma} and {Xi} axial coupling constants are also performed for the first time in a lattice calculation, g{sub {Sigma}{Sigma}} = 0.441(14) and g{sub {Xi}{Xi}} = -0.277(11).},

doi = {},

url = {https://www.osti.gov/biblio/924428},
journal = {},

number = ,

volume = ,

place = {United States},

year = {2007},

month = {6}

}