Related papers: Dispersive Approach to Chiral Perturbation Theory
The question of the asymptotic form of the perturbation expansion in scalar field theories is reconsidered. Renewed interest in the computation of terms in the epsilon-expansion, used to calculate critical exponents, has been frustrated by…
An exposition is made of recent developments using techniques of unitary chiral perturbation theory, $U \chi P T$, which allows one to extend predictions using chiral Lagrangians to higher energies than ordinary chiral perturbation theory,…
We include the eta-prime in chiral perturbation theory without employing 1/N_c counting rules. The method is illustrated by calculating the masses and decay constants of the Goldstone boson octet (pions, kaons, eta) and the singlet…
The chiral Lagrangian for Goldstone boson scattering is a power series expansion in numbers of derivatives. Each successive term is suppressed by powers of a scale, $\Lambda_\chi$, which must be less than of order $4\pi f/\sqrt{N}$ where…
We calculate the one-loop contributions to the difference \Delta_{\pi K} between the isoscalar on-shell pion-kaon scattering amplitude at the Cheng-Dashen point and the scalar form factor \Gamma_K (2M_\pi^2) in the framework of three flavor…
We perform a calculation of the isospin and hypercharge vector current propagators ($\Delta_{V33}^{\mu\nu}(q^2)$ and $\Delta_{V88}^{\mu\nu}(q^2)$) to two loops in chiral perturbation theory. The analysis is carried out with straightforward…
We show the results for the scattering poles associated to the rho, f0, a0, K*, sigma and kappa resonances in meson-meson scattering. Our amplitudes are obtained from the complete one-loop meson-meson scattering amplitudes from Chiral…
We match the results for the subthreshold parameters of pion-nucleon scattering obtained from a solution of Roy-Steiner equations to chiral perturbation theory up to next-to-next-to-next-to-leading order, to extract the pertinent low-energy…
We discuss $\pi\pi$ scattering in the framework of chiral perturbation theory. In particular, we recall the predictions made some time ago for the threshold parameters and for the phase shift difference $\delta_0^0-\delta_1^1$.
Combining large $N_C$ techniques and partial wave dispersion theory to analyze the $\pi\pi$ scattering, without relying on any explicit resonance lagrangian, some interesting results are derived: (a) a general KSRF relation including the…
We describe a novel framework for partially quenched chiral perturbation theory based on the replica method. The computational rules are exceedingly simple. We illustrate these rules by computing the partially quenched chiral condensate to…
The inverse-amplitude method is applied to the one-loop chiral expansion of the pion, kaon, and $K_{l3}$ form factors. Since these form factors are determined by the same chiral low-energy constants, it is possible to obtain finite…
We evaluate the two pion decay of the Roper resonance in a model where explicit re-scattering of the two final pions is accounted for by the use of unitarized chiral perturbation theory. Our model does not include an explicit $\epsilon$ or…
A brief survey of applications of chiral perturbation theory to both semileptonic and nonleptonic kaon decays is presented. Special emphasis is given to recent theoretical advances related to semileptonic decays, in particular pion pion…
We perform a calculation of the isospin and hypercharge axialvector current propagators to two loops in SU(3)xSU(3) chiral perturbation theory. A large number of order p^6 divergent counterterms are fixed, and complete two-loop renormalized…
In this talk I give a short introduction to hard pion Chiral Perturbation Theory and an overview of the available applications $K\to\pi\pi$, $B,D\to D,\pi,K,\eta$ semileptonic decays and $\chi_{c0,2}\to\pi\pi,KK$. It is pointed out that the…
Recent developments in low energy pion physics are reviewed, emphasizing the strength of dispersion theory in this context. As an illustration of the method, I discuss some consequences of the forward dispersion relation obeyed by the…
The relativistic amplitudes of pion photo- and electroproduction are calculated by dispersion relations at constant t. Several sum rules and low-energy theorems for the threshold amplitudes are investigated within this technique. The…
Integral equations for meson-baryon scattering amplitudes are obtained by utilizing time-ordered perturbation theory for a manifestly Lorentz-invariant formulation of baryon chiral perturbation theory. Effective potentials are defined as…
We have systematically calculated the S-wave pseudoscalar meson and decuplet baryon scattering lengths to the third order in the small scale expansion scheme of the heavy baryon chiral perturbation theory. We hope the future study may test…