We discuss the Pad\'e approximation to the $\pi\pi$ scattering amplitudes in 1--loop chiral perturbation theory. The approximation restores unitarity and can reproduce the correct resonance poles, but the approximation violates crossing symmetry and produce spurious poles on the complex $s$ plane and therefore plagues its predictions on physical quantities at quantitative level. However we find that one virtual state in the IJ=20 channel may have physical relevance
A non-perturbative method which combines constraints from chiral symmetry breaking and coupled chann...
First it is shown that the tree amplitude for pion–pion scattering in the minimal linear sigma mode...
In the absence of nucleons, we use partial wave unitarity, to show that the chiral expansion paramet...
We discuss the Pade approximation to the pi pi scattering amplitudes in one-loop chiral perturbation...
I describe the current status of the theory of pi pi scattering, reviewing in particular recent work...
We explore the meaning of single channel unitarity by analytically continuing the unitarity conditio...
The inverse amplitude method is used to unitarize the two-loop pipi scattering amplitudes of SU(2) c...
We calculate the pion-pion elastic scattering phase shifts for pion masses from the chiral limit to ...
The Bethe-Salpeter equation restores exact elastic unitarity in the s-channel by summing up an infin...
We review our recent one-loop calculation of all the two meson scattering amplitudes within SU(3) Ch...
The Bethe-Salpeter equation restores exact elastic unitarity in the s-channel by summing up an infin...
We review our recent study of the pion mass dependence of the p and a resonances, generated from one...
Using unitarized chiral perturbation theory methods, we perform a detailed analysis of the π π scatt...
It is explicitly shown that either the approximate solution of the integral equation for the invers...
It is demonstrated that for the isospin $I=1/2$ $\pi$N scattering amplitude, $T^{I=1/2}(s,t)$, $s={(...
A non-perturbative method which combines constraints from chiral symmetry breaking and coupled chann...
First it is shown that the tree amplitude for pion–pion scattering in the minimal linear sigma mode...
In the absence of nucleons, we use partial wave unitarity, to show that the chiral expansion paramet...
We discuss the Pade approximation to the pi pi scattering amplitudes in one-loop chiral perturbation...
I describe the current status of the theory of pi pi scattering, reviewing in particular recent work...
We explore the meaning of single channel unitarity by analytically continuing the unitarity conditio...
The inverse amplitude method is used to unitarize the two-loop pipi scattering amplitudes of SU(2) c...
We calculate the pion-pion elastic scattering phase shifts for pion masses from the chiral limit to ...
The Bethe-Salpeter equation restores exact elastic unitarity in the s-channel by summing up an infin...
We review our recent one-loop calculation of all the two meson scattering amplitudes within SU(3) Ch...
The Bethe-Salpeter equation restores exact elastic unitarity in the s-channel by summing up an infin...
We review our recent study of the pion mass dependence of the p and a resonances, generated from one...
Using unitarized chiral perturbation theory methods, we perform a detailed analysis of the π π scatt...
It is explicitly shown that either the approximate solution of the integral equation for the invers...
It is demonstrated that for the isospin $I=1/2$ $\pi$N scattering amplitude, $T^{I=1/2}(s,t)$, $s={(...
A non-perturbative method which combines constraints from chiral symmetry breaking and coupled chann...
First it is shown that the tree amplitude for pion–pion scattering in the minimal linear sigma mode...
In the absence of nucleons, we use partial wave unitarity, to show that the chiral expansion paramet...
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