Resonance Contributions to the Electromagnetic Low Energy Constants of Chiral Perturbation Theory
نویسنده
چکیده
The effective chiral Lagrangian of the strong and electromagnetic interactions of the pseudoscalar mesons at low energies depends on a set of low energy constants. We determine the contributions to the electromagnetic coupling constants at order O(ep), which arise from resonances within a photon loop. We give some implications of our results, in particular we discuss in detail the effects on the corrections to Dashen’s theorem. e-mail: [email protected] e-mail: [email protected]
منابع مشابه
Resonance Contributions to the Electromagnetic Low EnergyConstants of Chiral Perturbation
The eeective chiral Lagrangian of the strong and electromagnetic interactions of the pseudoscalar mesons at low energies depends on a set of low energy constants. We determine the contributions to the electromagnetic coupling constants at order O(e 2 p 2), which arise from resonances within a photon loop. We give some implications of our results, in particular we discuss in detail the eeects on...
متن کاملLow-Energy Constants from Resonance Chiral Theory
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 re...
متن کاملLarge N C in Chiral Resonance Lagrangians *
In the large Nc limit, Nc → ∞, at fixed scale ΛQCD, the spectrum of QCD is known to consist of an infinite number of stable states. The degrees of freedom in the corresponding low energy effective theory are the states with masses vanishing in the chiral limit (mu = md = ms = 0) of large Nc QCD, viz. π, K, η and η′.5 The presence of the remaining massive states shows up only indirectly, trough ...
متن کاملTowards a consistent estimate of the chiral low - energy constants ∗
Guided by the large-N C limit of QCD, we construct the most general chiral resonance Lagrangian that can generate chiral low-energy constants up to O(p 6). By integrating out the resonance fields, the low-energy constants are parametrized in terms of resonance masses and couplings. Information on those couplings and on the low-energy constants can be extracted by analysing QCD Green functions o...
متن کاملar X iv : 0 71 0 . 54 32 v 1 [ he p - ph ] 2 9 O ct 2 00 7 IFIC / 07 – 53 Electromagnetic low – energy constants in χ pt
We investigate three–flavour chiral perturbation theory including virtual photons in a limit where the strange quark mass is much larger than the external momenta and the up and down quark masses, and where the external fields are those of two–flavour chiral perturbation theory. In particular we work out the strange quark mass dependence of the electromagnetic two–flavour low–energy constants C...
متن کامل