# Chiral extrapolation of g{sub A} with explicit {delta}(1232) degrees of freedom

## Abstract

An updated and extended analysis of the quark-mass dependence of the nucleon's axial-vector coupling constant g{sub A} is presented in comparison with state-of-the-art lattice QCD results. Special emphasis is placed on the role of the {delta}(1232) isobar. It is pointed out that standard chiral perturbation theory of the pion-nucleon system at order p{sup 4} fails to provide an interpolation between the lattice data and the physical point. In constrast, a version of chiral effective field theory with explicit inclusion of the {delta}(1232) proves to be successful. Detailed error analysis and convergence tests are performed. Integrating out the {delta}(1232) as an explicit degree of freedom introduces uncontrolled errors for pion masses m{sub {pi}} > or approx. 300 MeV.

- Authors:

- Physik-Department, Theoretische Physik, Technische Universitaet Muenchen, D-85747 Garching (Germany)

- Publication Date:

- OSTI Identifier:
- 20933245

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevD.75.014503; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CHIRALITY; CONVERGENCE; COUPLING CONSTANTS; DEGREES OF FREEDOM; DELTA-1232 BARYONS; ERRORS; EXTRAPOLATION; INTERPOLATION; MASS; MEV RANGE 100-1000; NUCLEONS; PERTURBATION THEORY; PION-NUCLEON INTERACTIONS; PIONS; QUANTUM CHROMODYNAMICS; QUARKS

### Citation Formats

```
Procura, M., Musch, B. U., Hemmert, T. R., and Weise, W..
```*Chiral extrapolation of g{sub A} with explicit {delta}(1232) degrees of freedom*. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVD.75.014503.

```
Procura, M., Musch, B. U., Hemmert, T. R., & Weise, W..
```*Chiral extrapolation of g{sub A} with explicit {delta}(1232) degrees of freedom*. United States. doi:10.1103/PHYSREVD.75.014503.

```
Procura, M., Musch, B. U., Hemmert, T. R., and Weise, W.. Mon .
"Chiral extrapolation of g{sub A} with explicit {delta}(1232) degrees of freedom". United States.
doi:10.1103/PHYSREVD.75.014503.
```

```
@article{osti_20933245,
```

title = {Chiral extrapolation of g{sub A} with explicit {delta}(1232) degrees of freedom},

author = {Procura, M. and Musch, B. U. and Hemmert, T. R. and Weise, W.},

abstractNote = {An updated and extended analysis of the quark-mass dependence of the nucleon's axial-vector coupling constant g{sub A} is presented in comparison with state-of-the-art lattice QCD results. Special emphasis is placed on the role of the {delta}(1232) isobar. It is pointed out that standard chiral perturbation theory of the pion-nucleon system at order p{sup 4} fails to provide an interpolation between the lattice data and the physical point. In constrast, a version of chiral effective field theory with explicit inclusion of the {delta}(1232) proves to be successful. Detailed error analysis and convergence tests are performed. Integrating out the {delta}(1232) as an explicit degree of freedom introduces uncontrolled errors for pion masses m{sub {pi}} > or approx. 300 MeV.},

doi = {10.1103/PHYSREVD.75.014503},

journal = {Physical Review. D, Particles Fields},

number = 1,

volume = 75,

place = {United States},

year = {Mon Jan 01 00:00:00 EST 2007},

month = {Mon Jan 01 00:00:00 EST 2007}

}