Related papers: P-wave pi pi amplitude from dispersion relations
The invariant amplitudes for pion electroproduction on the nucleon are evaluated by dispersion relations at constant t with MAID as input for the imaginary parts of these amplitudes. In the threshold region these amplitudes are confronted…
We discuss the recent literature on the treatment of final state interactions in K -> pi pi. Various approaches are compared and particular emphasis is given to the possibility of combining dispersive methods with lattice input. Recent…
In this work we construct the $\pi\pi$ scattering amplitude $T^0_0$ with regular analytical properties in the $s$ complex plane, which describes simultaneously the data on the $\pi\pi$ scattering, $\phi\to\pi^0\pi^0\gamma$ decay, and…
The scattering of $\gamma \pi \to \pi \pi$ is studied using the axial anomaly, elastic unitarity, analyticity and crossing symmetry. Using the technique to derive the Roy's equation, an integral equation for the P-wave amplitude is obtained…
Strichartz-type estimates for one-dimensional surface water-waves under surface tension are studied, based on the formulation of the problem as a nonlinear dispersive equation. We establish a family of dispersion estimates on time scales…
We study the dispersive properties of the wave equation associated with the shifted Laplace-Beltrami operator on Damek-Ricci spaces, and deduce Strichartz estimates for a large family of admissible pairs. As an application, we obtain global…
We determine elastic and coupled-channel amplitudes for isospin-1 meson-meson scattering in $P$-wave, by calculating correlation functions using lattice QCD with light quark masses such that $m_\pi = 236$ MeV in a cubic volume of $\sim (4…
Resonant scattering of fast particles off low frequency plasma waves is a major process determining transport characteristics of energetic particles in the heliosphere and contributing to their acceleration. Usually, only Alfv\'en waves are…
If the Electroweak Symmetry Breaking Sector turns out to be strongly interacting, the actively investigated effective theory for longitudinal gauge bosons plus Higgs can be efficiently extended to cover the regime of saturation of unitarity…
We comment on a recent paper by Weiser et al. [Phys. Rev. C {\bf 54}, 1930 (1996)]. The authors have performed a single-energy analysis of $\pi^+ p$ scattering data at 68.3 MeV, finding a value for the $S_{31}$ phase shift about 1^o smaller…
In this paper we discuss some properties of linear fractional dispersive waves. In particular, we compare the dispersion relations emerging from the kinematic wave equation and from the linearised Korteweg - de Vries equation with the…
Making use of a derivative dispersion approach, we investigate the behavior of the the total cross section and the rho parameter for pp and p(bar)p scattering from accelerator to cosmic ray energies. The discrepancies in the cosmic ray…
We review the use of new and precise dispersive equations, which also implement crossing symmetry, in order to shed further light on the long-standing puzzle in the parameters of the f0(500), as well as the f0(980). This puzzle is finally…
We consider the $\pi\pi$ scattering amplitude obtained by Colangelo, Gasser and Leutwyler (CGL), using dispersion relations and chiral perturbation theory to two loops. We point out that the input used by CGL for energies above 1.42 GeV is…
A joint analysis of the pi+pi- and pi0pi0 S-wave amplitudes including results of three experiments has been performed. Using our theoretical model of the pion-pion production in which not only the pion exchange but also the a1(1260) meson…
The results of the recent experiments on the reaction $\pi^-p\to\pi^0\pi^0n$ performed at KEK, BNL, IHEP, and CERN are analyzed in detail. For the I=0 $\pi\pi$ S wave phase shift $\delta^0_0$ and inelasticity $\eta^0_0$ a new set of data is…
This paper is devoted to the study of the leading twist distribution amplitudes of P-wave nonrelativistic mesons. It is shown that at the leading order approximation in relative velocity of quark-antiquark pair inside the mesons these…
We study the nature of the scalar D_0 meson from the viewpoint of chiral symmetry. With the linear representation of chiral symmetry, we construct the D pi scattering amplitude satisfying the chiral low-energy theorem, in which the D_0…
We discuss the simultaneous dispersive analyses of $\pi K\to \pi K$ and $\pi \pi \to K \bar{K}$ scattering data and the $\kappa/K^*_0(700)$ resonance. The unprecedented statistics of present and future Hadron Experiments, modern Lattice QCD…
A new dispersion relation for the partial wave $\pi\pi$ scattering $S$ matrix is set up. Using the dispersion relation we generalize the single channel unitarity condition, $SS^+=1$, to the entire complex $s$ plane, which is equivalent to…