Low-Energy Constants from Resonance Chiral Theory

Abstract

I discuss the recent attempts to build an effective chiral Lagrangian incorporating massive resonance states. A useful approximation scheme to organize the resonance Lagrangian is provided by the large-Nc limit of QCD. Integrating out the resonance fields, one recovers the usual chiral perturbation theory Lagrangian with explicit values for the low-energy constants, parameterized in terms of resonance masses and couplings. The resonance chiral theory generates Green functions that interpolate between QCD and chiral perturbation theory. Analyzing these Green functions, both for large and small momenta, one gets QCD constraints on the resonance couplings and, therefore, information on the low-energy constants governing the Goldstone interactions.

Proceedings of the 8th International Conference on Quark Confinement and the Hadron Spectrum (Mainz, Germany, 1-6 September 2008). 10 pages

References in corpus (3)

• Effective Field Theory
• Colourless Mesons in a Polychromatic World
• Determination of the Chiral Couplings L_10 and C_87 from Semileptonic Tau Decays

Cited by in corpus (6)

• The vector form factor at the next-to-leading order in 1/N(C): chiral couplings L9(mu) and C88(mu) - C90(mu)
• Generalized Skyrmions in QCD and the Electroweak Sector
• High energy constraints in the octet SS-PP correlator and resonance saturation at NLO in 1/Nc
• Indications on the Mass of the Lightest Electroweak Baryon
• Lifetime of the eta' meson at low temperature
• Weinberg sum rules at NLO in 1/Nc