Related papers: Understanding I=2 pi-pi Interaction
The phases of terms of amplitude that arise from the $\pi\pi$ interaction are obtained by using a simple realistic model of $\pi\pi$ interaction via virtual $\rho$-meson, instead of the ChPT. It is shown that the standard ChPT approach…
We calculate the parameters describing elastic $I=1$, $P$-wave $\pi\pi$ scattering using lattice QCD with $2+1$ flavors of clover fermions. Our calculation is performed with a pion mass of $m_\pi \approx 320\:\:{\rm MeV}$ and a lattice size…
Knowledge of the details of the $S$-wave $K\pi$ and $\pi\pi$ systems limits the precision of measurements of heavy quark meson properties. This talk covers recent experimental developments in parametrizing and measuring these waves, and…
Motivated by the presence of nearby thresholds in other baryon-meson channels with I=1 and S=-1, we investigate whether the Lambda pi scattering phase shifts at a center-of-mass energy equal to the Xi mass could be larger than suggested by…
Starting from hyperbolic dispersion relations for the invariant amplitudes of pion-nucleon scattering together with crossing symmetry and unitarity, one can derive a closed system of integral equations for the partial waves of both the…
The problem of scalar mesons still remains a challenging puzzle, for which we do not even know which are the right pieces to set up. The proliferation of resonances (some of them are very broad and appear on top of hadronic thresholds) and…
The amplitude for the anomalous transitions gamma pi(+) -> pi(0) pi(+) is analyzed within Chiral Perturbation Theory including electromagnetic interactions. The presence of a t-channel one-photon exchange contribution induces sizeable e^2…
We give the conversion equations which lead from experimental values of the $3p \to 1s$ transition energy in pionic hydrogen and the total width of the $1s$ level to values of the s-wave threshold scattering parameters for the processes…
We present a model for the decay D+ --> K- pi+ pi+. The weak interaction part of this reaction is described using the effective weak Hamiltonian in the factorisation approach. Hadronic final state interactions are taken into account through…
The scattering phase shift encodes a good amount of physical information which can be used to study resonances from scattering data. Among others, it can be used to calculate the continuum density of states and the collision time in a…
The theoretical predictions for the subtraction constants lead to a very accurate dispersive representation of the pi pi scattering amplitude below 0.8 GeV. The extension of this representation up to the maximum energy of validity of the…
In this work we provide a dispersive analysis of $\pi\pi \rightarrow K\bar{K}$ scattering. For this purpose we present a set of partial-wave hyperbolic dispersion relations using a family of hyperbolas that maximizes the applicability range…
A distorted-wave method is used to analyse nucleon-nucleon scattering in the 1S0 channel. Effects of one-pion exchange are removed from the empirical phase shift to all orders by using a modified effective-range expansion. Two-pion exchange…
We express the leading electromagnetic corrections in K-> pi pi amplitudes as integrals over the virtual photon squared-momentum Q^2. The high Q^2 behavior is obtained via the operator product expansion. The low Q^2 behavior is calculated…
The $\pi N$ potential includes the t-channel exchanges of the scalar-mesons $\sigma$ and f_0, vector-meson $\rho$, tensor-mesons f_2 and f_2' and the Pomeron as well as the s- and u-channel exchanges of the nucleon N and the resonances…
We calculate the electromagnetic corrections to the isospin invariant mixing angle and to the two eigenphases for the $s$-, $p_{1/2}$- and $p_{3/2}$-partial waves for $\pi^- p$ elastic and charge exchange scattering. These corrections have…
The $\pi\pi$ scattering amplitude with regular analytical properties in the $s$ complex plane has been constructed. It describes simultaneously the data on the $\pi\pi$ scattering, $\phi\to\pi^0\pi^0\gamma$ decay and $\pi\pi\to K\bar K$…
We present results of phase shift for I=2 $S$-wave $\pi\pi$ system with the Wilson fermions in the quenched approximation. The finite size method proposed by L\"uscher is employed, and calculations are carried out at $\beta=5.9$…
The pion mass difference generates a pronounced cusp in K --> 3 pi decays. As has recently been pointed out by Cabibbo and Isidori, an accurate measurement of the cusp may allow one to pin down the S-wave pi pi scattering lengths to high…
We impose unitarity constraints on the S-wave isoscalar pion-pion amplitudes extracted from the analysis of the pi- p ---> pi+ pi- n data which have been measured by the CERN-Cracow-Munich collaboration on a transversely polarized target at…