Related papers: pi K scattering inputs to ChPT
A system of dispersive representations of the Omn\`es-Khuri-Treiman-Sawyer-Wali type for the final-state interactions in the amplitudes of the $K\to\pi\pi\pi$ weak transitions is constructed, under the assumptions that CP and isospin…
We simulate K pi scattering in s-wave and p-wave for both isospins I=1/2, 3/2 using quark-antiquark and meson-meson interpolating fields. We extract the elastic phase shifts delta at several values of the K-pi relative momenta. The…
This paper presents the results of an analysis of the low-energy $\pi^\pm p$ differential cross sections, acquired by the CHAOS Collaboration at TRIUMF \cite{chaos,denz}. We first analyse separately the $\pi^+ p$ and the $\pi^- p$…
We evaluate energy levels of the K-pi system in the K* channel in finite volume using chiral unitary theory. We use these energy levels to obtain K-pi phase shifts, and then obtain the K* mass and its decay width. We investigate their…
We study relativistic scattering when one only has access to a subset of the particles, using the language of quantum measurement theory. We give an exact, non-perturbative formula for the von Neumann entanglement entropy of an apparatus…
We present an extraction of the pion-nucleon ($\pi N$) scattering lengths from low-energy $\pi N$ scattering, by fitting a representation based on Roy-Steiner equations to the low-energy data base. We show that the resulting values confirm…
We use a dispersion representation based on unitarity and analyticity to study the low energy $\gamma^* N\rightarrow \pi N$ process in the $S_{11}$ channel. Final state interactions among the $\pi N$ system are critical to this analysis.…
In this paper, we consider the scattering theory for acoustic-type equations on non-compact manifolds with a single flat end. Our main purpose is to show an existence result of non-scattering energies. Precisely, we show a Weyl-type lower…
This report summarizes recent calculations of low-energy hadron-hadron scattering amplitudes in the nonrelativistic quark potential model, which assume that the scattering mechanism is a single interaction (usually OGE) followed by…
We report on our determination of the values of the one and two loop low energy constants appearing in the Chiral Perturbation Theory calculation of the pi-pi scattering amplitude. For this we use a precise sum rule determination of…
The hyperbolic version of Roy-Steiner equation describing low energy $\pi N$ scatterings, with larger analyticity domain in the complex $s$ plane is solved. The numerical results on phase shifts of low partial waves are in agreement with…
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…
It is shown that the low energy coefficients of the next-to-leading order (NLO) chiral perturbation theory needed to determine $\Delta I=1/2$, $K\to\pi\pi$ decay amplitudes can be fixed by calculating $K\pi\to\pi$ amplitudes on lattice.…
The Compton scattering on a charged pion and the process \gamma\gamma \to \pi^0\pi^0 are studied using the dispersion relations. Unknown parameters of the S-wave \pi\pi interaction, represented as a board Breit-Wignar resonance, and a sum…
Weinberg's theorem for \pi-\pi scattering, including the Adler zero at threshold in the chiral limit, is analytically proved for microscopic quark models that preserve chiral symmetry. Implementing Ward-Takahashi identities, the isospin 0…
I discuss low-energy pion-nucleon scattering in the framework of chiral perturbation theory. I argue that using this theoretical method one is able to handle the in some cases tremendous experimental accuracy (for the low partial waves). I…
A general theoretical framework is developed for interpreting spectropolarimetric observations of optically thin emission line scattering from small dust particles. Spatially integrated and spatially resolved line profiles of both scattered…
Using holographic models where chiral symmetry is broken through IR b.c.'s, we determine a novel set of relations between QCD matrix elements. In particular, we find that the amplitudes of the three processes pi pi->pi pi, gamma gamma->pi…
We evaluate the contribution of pion-pion rescattering to the $p p \to p p \pi^+ \pi^-$ and $p \bar p \to p \bar p \pi^+ \pi^-$ reactions. We compare our results with the close-to-threshold experimental data. The pion-pion rescattering…
Recently the nucleon-nucleon interaction derived using time-ordered perturbation theory in manifestly Lorentz-invariant chiral effective field theory was shown to yield promising results for peripheral neutron-proton scattering. In this…