Related papers: Comparing partial-wave amplitude parametrization w…
Exclusive and kinematically complete high-statistics measurements of quasifree polarized $\vec{n}p$ scattering have been performed in the energy region of the narrow resonance structure $d^*$ with $I(J^P) = 0(3^+)$, $M \approx$ 2380…
I summarize the status of the $\Delta I=1/2$ rule in $K\to\pi\pi$ decays within an {\it analytic} approach based on the dual representation of QCD as a theory of weakly interacting mesons for large $N$, where $N$ is the number of colours.…
Model independent formulae are derived for the beam analyzing power $A_y$ and beam to meson spin transfers in $pp \to pp \omega$ taking into consideration all the six threshold partial wave amplitudes covering the $Ss, Sp$ and $Ps$…
We compare the strong part of the $\bar{\hbox{N}}\hbox{N}$ interaction obtained by the Nijmegen partial wave analysis and the results of some of the most popular $\bar{\hbox{N}}\hbox{N}$ optical potentials in configuration space. We have…
We present a simple one-dimensional example of a spin 1/2 particle submitted to a delta-type potential which interacs differently with the two components of the wavefunction and to an external magnetic field. It has two coupled channels,…
The resonant electric quadrupole amplitude in the transition $\gamma N\leftrightarrow\Delta(1232)$ is of great interest for the understanding of baryon structure. Various dynamical models have been developed to extract it from the…
Single-energy partial-wave analysis has often been applied as a way to fit data with minimal model dependence. However, remaining unconstrained, partial waves at neighboring energies will vary discontinuously because the overall amplitude…
Baryon to meson transition distribution amplitudes (TDAs) extend the concept of generalized parton distributions. Baryon to meson TDAs appear as building blocks in the collinear factorized description of amplitudes for a class of hard…
We evaluate the $\pi N$ compositeness of the $\Delta (1232)$ resonance so as to clarify the internal structure of $\Delta (1232)$ in terms of the $\pi N$ component. Here the compositeness is defined as contributions from two-body wave…
Several methods for the treatment of pion photoproduction in the region of the Delta(1232) resonance are discussed, in particular the effective Lagrangian approach and the speed plot analysis are compared to a dynamical treatment. As a main…
In this manuscript we discuss the results of our recent study on $\Xi$ resonances. We have studied meson-baryon interaction with strangeness $-2$ by solving scattering equations in a coupled channel approach and found that the dynamics…
We study the coupling of a tetraquark system to an exchanged meson-meson channel, using a pure gluonic theory based four-quark potential {\em matrix} model which is known to fit well a large number of data points for lattice simulations of…
Nucleon $\to \Delta(1232)$ transition electroweak form factors are discussed in a single pion production model with nonresonant background terms originating from a chiral perturbation theory. Fits to electron-proton scattering $F_2$ as well…
Properties of nucleon and $\Delta$ resonances are derived from a multichannel partial wave analysis. The statistical significance of pion and photo-induced inelastic reactions off protons are studied in a multichannel partial-wave analysis.
The meson scattering and electroproduction amplitudes in the D13, D33 and D15 partial waves are calculated in a coupled-channel formalism incorporating quasi-bound quark-model states, extending our previous studies of the P11, P33 and S11…
We construct the $\Delta$ resonance as a superposition of a bare $\Delta$ state and the $\pi N$ continuum. It is parametrized by three coupling constants for local $\pi N \Delta$ and $\pi \pi N N$ couplings and the $\Delta$ mass. The latter…
The renormalization of the chiral nuclear interactions is studied. In leading order, the cutoff dependence is related to the singular tensor interaction of the one-pion exchange potential. In S waves and in higher partial waves where the…
We study the correlation between $\epe$ and $\Delta I=1/2$ rule in the framework of non-linear $\sigma$ model including scalar mesons. The matrix elements of QCD and Electroweak (EW) penguin operators are computed within factorization…
The NN scattering problem is usually analyzed in terms of partial waves and the corresponding coupled channel phase-shifts and mixing angles, but the available experiments induce correlations amongst the corresponding channels with…
We consider meson-baryon interactions in S-wave with strangeness -1. This is a sector populated by plenty of resonances interacting in several two-body coupled channels. We consider a large set of experimental data, where the recent…