2006/10/31 by Massimiliano Procura, M. Procura, Bernhard Musch +4
Mathematics · Physics and Astronomy · #Chiral perturbation theory #Extrapolation #High-Energy Particle Collisions Research #Lattice (music) #Lattice QCD #Mathematical analysis #Mathematical physics #Mathematics #Nucleon #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #hep-lat
paper · pdf · doi:10.1103/physrevd.75.014503
published as Phys.Rev.D75:014503,2007 · 25 pages, 12 figures, 2 tables; v2: minor changes
openalex publication_date 2007/01/12 · arxiv created 2007/03/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
An updated and extended analysis of the quark-mass dependence of the nucleon's axial-vector coupling constant gA is presented in comparison with state-of-the-art lattice QCD results. Special emphasis is placed on the role of the \ensuremathΔ(1232) isobar. It is pointed out that standard chiral perturbation theory of the pion-nucleon system at order p4 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 \ensuremathΔ(1232) proves to be successful. Detailed error analysis and convergence tests are performed. Integrating out the \ensuremathΔ(1232) as an explicit degree of freedom introduces uncontrolled errors for pion masses m_\ensuremathπ\ensuremath\gtrsim300 MeV.