Chiral extrapolation of g{sub A} with explicit {delta}(1232) degrees of freedom
- Physik-Department, Theoretische Physik, Technische Universitaet Muenchen, D-85747 Garching (Germany)
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.
- OSTI ID:
- 20933245
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 75, Issue 1; Other Information: DOI: 10.1103/PhysRevD.75.014503; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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