Related papers: Lambda(1405) poles obtained from pi0-Sigma0 photop…
We investigate the structure of the Lambda(1405) resonance and Kbar N phenomenology in the perspective of chiral SU(3) dynamics. Utilizing the chiral coupled-channel approach which well describes the Kbar N scattering observable, we perform…
The cross section for the pd --> ^3He eta pi0 reaction has been measured at a beam energy of 1450 MeV using the WASA detector at the CELSIUS storage ring and detecting one ^3He and four photons from the decays of the two photons. The data…
We study the production of Sigma^+-pi^+-pK^+ particle quartets in p+p reactions at 3.5 GeV kinetic beam energy. The data were taken with the HADES experiment at GSI. This report evaluates the contribution of resonances like Lambda(1405$,…
We report here differential cross sections for the reaction $\gamma p \to K^{*0}\Sigma^+$ for the first time with high statistics. The measurements were done using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Data were…
We perform a combined analysis of antikaon-nucleon scattering cross sections and the recent SIDDHARTA kaonic hydrogen data in the framework of a coupled-channel Bethe-Salpeter approach at next-to-leading order in the chiral expansion of the…
Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector for photon energies between 0.92 and 1.68~GeV at the electron accelerator ELSA. The beam asymmetry~$\Sigma$ has been extracted for $115^\circ < \theta_{\rm…
We show that the recently measured asymmetry in helicity-angle spectra of the Lambda-hyperons produced in the reaction pp -> K^+Lambda p reaction and the energy dependence of the total pp -> K^+Lambda p cross section can be explained…
Since the discovery of the $\Lambda(1405)$, it remains poorly described by conventional constituent quark models, and it is a candidate for having an "exotic" meson-baryon or "penta-quark" structure, similar to states recently reported in…
We present a preliminary analysis of the photon beam asymmetry observable (Sigma) from the photoproduction reaction channel gamma+ n -> p + pi-. This new data was obtained using the near-4pi CEBAF Large Acceptance Spectrometer (CLAS) at…
We investigate the reaction mechanism of $K^0 \Lambda$ photoproduction off the neutron target, i.e., $\gamma n \to K^0 \Lambda$, in the range of $W\approx 1.6-2.2$ GeV. We employ an effective Lagrangian method at the tree-level Born…
The yield of the $^{16}$O$(\gamma ,\pi^{+} p)$ reaction has been measured in the region of the excitation of the $\Delta(1232)$ isobar at high momentum transfers to the residual nuclear system. The experimental data are interpreted within…
A fit of the experimental data to the total cross section of the process \gamma\gamma->\pi^0\pi^0 in the energy region from 270 to 2250 MeV has been carried out using dispersion relations for the invariant amplitudes where the quadrupole…
The pp -> p K+ Y0 reaction has been studied for hyperon masses m(Y0)<1540 MeV/c2 at COSY-Juelich by using a 3.65 GeV/c circulating proton beam incident on an internal hydrogen target. Final states comprising two protons, one positively…
The interaction of Lambda*=Lambda(1405) with a nucleon is studied from the viewpoint of chiral dynamics. We construct the coordinate space Lambda* N potential in the meson-exchange picture, which serves as a fundamental ingredient for the…
A gauge-invariant model is constructed for the $\gamma p \to K^+\Lambda(1690)$ reaction within a tree-level effective Lagrangian approach with the purpose to understand the underlying production mechanisms and to study the resonance…
It is shown, that fitting parameters of a $\bar{K}N$ interaction model to different sets of experimental data can lead to physical conclusions which might provide a deeper insight into the physics of this multichannel system. The available…
A model of $\pi N$ pair photoproduction on nuclei at high momentum transfer is presented. The $A(\gamma,\pi N)B$ reaction amplitude is obtained by means of an extended impulse approximation, according to which the nuclear wavefunction…
A precision measurement of the differential cross sections $d\sigma/d\Omega$ and the linearly polarized photon asymmetry $\Sigma \equiv (d\sigma_\perp - d\sigma_\parallel) \slash (d\sigma_\perp + d\sigma_\parallel)$ for the $\vec{\gamma} p…
We study the reactions $\gamma\gamma\rightarrow \pi^0\pi^0$, $\pi^+\pi^-$, $K^0\bar{K}^0$, $K^+K^-$, $\eta \eta$ and $\pi^0\eta$ based on a chiral Lagrangian with dynamical light vector mesons as formulated within the hadrogenesis…
We propose a novel method to identify the two-pole structure of the $\Lambda(1405)$. The two poles owe their origin to different quark flavor irreducible representations in the meson-baryon coupled-channel interactions, thus they should be…