Related papers: Double and single pion photoproduction within a dy…

In this talk we report on two physical processes, the photoproduction of $\rho$ mesons in nuclei and the $\pi^0 \pi^0$ photoproduction in nuclei at low energies. In the first case the aim is to observe experimentally the theoretically…

A dynamical coupled-channel formalism for processes $\pi N \to KY$ and $\gamma N \to KY$ is presented which provides a comprehensive investigation of recent data on the $\gamma p \to K^+ \Lambda$ reaction. The non-resonant interactions…

The role of the nucleon resonances in the double polarization observables of pion photoproduction is investigated by using the resonance parameters predicted by Capstick and Roberts. As an example, we show that the not-well-determined…

A dynamical coupled-channels (DCC) model for neutrino-nucleon reactions in the resonance region is developed. Starting from the DCC model that we have previously developed through an analysis of $\pi N, \gamma N\to \pi N, \eta N, K\Lambda,…

Forward photoproduction of $\pi^+\pi^-$ pairs with invariant mass of the order of $m_\rho\sim 770$ MeV is traditionally understood to be produced via Pomeron exchange. Based on a detailed analysis of the CLAS photoproduction data, it is…

We explore the photoproduction mechanisms for charged and neutral pion pairs off a heavy nucleus at threshold. We calculate the production of charged pairs in the Coulomb field of the nucleus in the Born approximation using explicit…

A dynamical coupled-channels formalism is used to investigate the $\eta-$meson production mechanism on the proton induced by pions, in the total center-of-mass energy region from threshold up to 2 GeV. We show how and why studying…

Pion induced reactions provide unique opportunities for an unambiguous description of baryonic resonances and their coupling channels by means of a partial wave analysis. Using the secondary pion beam at SIS18, the two pion production in…

The differential cross section of the process gamma gamma -> pi^0 pi^0 has been measured in the kinematical range 0.6 GeV < W < 4.0 GeV and |cos theta*|<0.8 in energy and pion scattering angle, respectively, in the gamma gamma…

We have measured the differential cross section for the gamma n --> pi- p and gamma p --> pi+ n reactions at center of mass angle of 90 degree in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at photon…

The first measurement is reported of the double-polarization observable G in photoproduction of neutral pions off protons, covering the photon energy range from 620 to 1120 MeV and the full solid angle. G describes the correlation between…

The J\"ulich-Bonn dynamical coupled-channel approach is extended to include $K\Sigma$ photoproduction off the proton. Differential cross section and (double) polarization data for $K^+\Sigma^0$ and $K^0\Sigma^+$ are analysed simultaneously…

The single-pion production reactions $pp\to d\pi^+$, $pp\to np\pi^+$ and $pp\to pp\pi^0$ were measured at a beam momentum of 0.95 GeV/c ($T_p \approx$ 400 MeV) using the short version of the COSY-TOF spectrometer. The central calorimeter…

The incoherent pion photoproduction reaction gd-->pi-pp is considered theoretically in a wide energy region Eth =< Eg =< 2700 MeV. The model applied contains the impulse approximation as well as the NN- and piN-FSI amplitudes. The aim of…

Pion photo- and electroproduction has been studied at threshold and in the resonance region below W=2GeV. At threshold pi^0 production can be very well explained within a dynamical model derived from an effective chiral Lagrangian. The…

A resonance model for two-pion production in the pion-nucleon reaction is developed that includes information obtained in the analysis of pion-nucleon scattering in a meson-exchange model. The baryonic resonances Delta(1232), N*(1440),…

Two-pion photoproduction in the reaction gamma p -> p pi+ pi- has been studied at Jefferson Lab Hall B using a circularly-polarized tagged photon beam in the energy range between 0.6 GeV and 2.3 GeV. Beam-helicity-dependent angular…

A Regge model with absorptive corrections is employed in a global analysis of the world data on the reactions gamma p -> pi0 p and gamma n -> pi0 n for photon energies from 3 to 18 GeV. In this region resonance contributions are expected to…

We develop a dynamical coupled-channels (DCC) model for neutrino-nucleon reactions in the resonance region, by extending the DCC model that we have previously developed through an analysis of $\pi N, \gamma N\to \pi N, \eta N, K\Lambda,…

Recent CLAS data on the $p\pi^+\pi^-$ electroproduction off protons at 1.3$<$W$<$1.57 GeV and 0.25$<$$Q^{2}$$<$0.6 GeV$^{2}$ have been analyzed using a meson-baryon phenomenological model. By fitting nine 1-fold differential cross section…