Related papers: Pion photoproduction in a dynamical coupled-channe…
Pion photoproduction reactions are investigated in a dynamical coupled-channel approach based on the Juelich pi-N model, which presently includes the hadronic pi-N and eta-N stable channels as well as the pi-Delta, sigma-N and rho-N…
The photoproduction of pion off nucleon is investigated within a dynamical coupled-channels approach based on the Juelich pi-N model, which has been quite successful in the description of pi-N to pi-N scattering for center-of-mass energies…
The reactions $\gamma p\to\pi^0 p$ and $\gamma p\to\pi^+ n$ are analyzed in a semi-phenomenological approach up to $E\sim2.3$ GeV. Fits to differential cross section and single and double polarization observables are performed. A good…
Within a dynamical coupled-channels model which has already been fixed from analyzing the data of the pi N -> pi N and gamma N -> pi N reactions, we present the predicted double pion photoproduction cross sections up to the second resonance…
The electromagnetic pion production reactions are investigated within the dynamical coupled-channels model developed in {\bf Physics Reports, 439, 193 (2007)}. The meson-baryon channels included in this study are $\gamma N$, $\pi N$, $\eta…
Based on an effective field theory of hadrons in which quantum chromodynamics is assumed to provide the necessary bare cutoff functions, a gauge-invariant theory of pion photoproduction with fully dressed nucleons is developed. The…
We present a relativistic dynamical model of pion photoproduction on the nucleon in the resonance region. It offers several advances over the existing approaches. The model is obtained by extending our $\pi N$-scattering description to the…
A dynamical coupled channel approach is used to study $\pi$ and $\omega$--meson production induced by pions and photons scattering from the proton. Six intermediate channels including $\pi N$, $\eta N$, $\pi\Delta$, $\sigma N$, $\rho N$ and…
The $\eta N$ final state is isospin-selective and thus provides access to the spectrum of excited nucleons without being affected by excited $\Delta$ states. To this end, the world database on eta photoproduction off the proton up to a…
Based on an effective field theory of hadrons in which quantum chromodynamics is assumed to provide the necessary bare cutoff functions, a gauge-invariant theory of pion photoproduction with fully dressed nucleons is described. The…
We investigate pion photoproduction off the proton in a manifestly gauge-invariant chiral unitary extension of chiral perturbation theory. In a first step, we consider meson-baryon scattering taking into account all next-to-leading order…
The nonresonant mechanism in the reactions $e^+\,e^-\to \pi^-\,p\,\bar{n}$ and $e^+\,e^-\to \pi^+\,n\,\bar{p}$ is investigated in frame of the one-photon exchange approximation. The description of the hadronic phase space and the invariant…
An effective field theory with hadrons and photons is constructed, where the hadronic parameters are determined by fitting elastic $\pi$N scattering data. The predicted pion-induced $\eta$-production on the nucleon agrees well with the…
The pion- and photon induced reactions for the final states $\gamma N$, $\pi N$, $2\pi N$, $\eta N$, and $\omega N$ are studied within a coupled-channel effective Lagrangian approach in the energy region from the pion threshold up to 2 GeV.…
We present a detailed quark-model study of pion photoproduction within the effective Lagrangian approach. Cross sections and single-polarization observables are investigated for the four charge channels, $\gamma p\to \pi^+ n$, $\gamma n\to…
A dynamical coupled-channel model is presented for investigating the nucleon resonances in the meson production reactions induced by pions and photons. The model is based on an energy-independent Hamiltonian which is derived from a set of…
As a step toward performing a complete coupled-channels analysis of the world data of pi N, gamma^* N --> pi N, eta N, pi pi N reactions, the pi N --> pi pi N reactions are investigated starting with the dynamical coupled-channels model…
Results of a relativistic model for pion- and photon-induced reactions on the proton are presented. The model is crossing symmetric and gauge invariant. The nucleon resonances P_11 (1440), P_11 (1710), D_13 (1520), S_11 (1535), S_11 (1650),…
A chiral quark-model approach is adopted to study the $\gamma p\rightarrow \pi^0p$ and $\gamma n\rightarrow \pi^0 n$ reactions. Good descriptions of the total and differential cross sections and single-polarization observables are obtained…
The Ward-Takahashi identities are central to the gauge invariance of the photoproduction amplitude. Here we demonstrate that unitarity and in particular the inclusion of both the $\pi N$ and $\gamma\pi N$ thresholds on equal footing yields…