Related papers: A new candidate for non-strangeness pentaquarks: N…
Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were…
The positive--strangeness baryon resonance $\Theta^+$ is observed in photoproduction of the $\rm nK^+K^0_s$ final state with the SAPHIR detector at the Bonn ELectron Stretcher Accelerator ELSA. It is seen as a peak in the $\rm nK^+$…
Re-analyzing the old pi N --> K Lambda data, the additional proof is given for the existence of the N(1710) P11 state, critically needed in light of reported observations of exotic Theta(1539) and Xi(1862) pentaquarks. An existing…
The nucleon-like member $N(1685)$ of the speculative baryon antidecuplet denotes one possible explanation for the narrow peak-structure around $W = 1.68$ GeV observed in the total cross section of $\eta$-photoproduction off the neutron. If…
A new experiment is proposed with the aim to study eta-mesic nuclei and low-energy interactions of eta with nuclei. Two decay modes of eta produced by a photon beam inside a nucleus will be observed, namely a collisional decay \eta N \to…
We discuss the implications of the suggested interpretation of the recently reported narrow pi N resonance (width \approx 25 MeV at 1680 MeV) as a pentaquark in the same multiplet as the Theta+. We consider a diquark-triquark pentaquark…
The photoproduction reaction of $\gamma p \to \eta^\prime p$ is investigated based on an effective Lagrangian approach in the tree-level approximation, with the purpose being to understand the reaction mechanisms and to extract the…
We perform an updated coupled-channel analysis of eta-meson production including all recent photoproduction data on the proton. The dip observed in the differential cross sections at c.m. energies W=1.68 GeV is explained by destructive…
Incoherent photoproduction of eta-mesons on the deuteron is considered. The main attention is paid to the region above the S11(1535) resonance where rather narrow resonance like structure in the total cross section extracted for gamma n ->…
We claim that a narrow peak in the cross section near 1685~MeV in the $\gamma n\to \eta n$ channel can be explained through a peculiar radial behaviour of the $p$-wave quark states with $j=1/2$ and $j=3/2$ in the low lying S11 resonances…
Within a chiral constituent quark model approach, $\eta$-meson production on the proton {\it via} electromagnetic and hadron probes are studied. With few parameters, differential cross-section and polarized beam asymmetry for \gamma p \to…
The reactions of $K \Sigma(1385)$ photoproduction, i.e., $\gamma p \to K^+ \Sigma^0(1385)$ and $\gamma n \to K^+ \Sigma^-(1385)$, are investigated in the resonance energy region for studying the role of the nucleon and $\Delta$ resonances…
Differential cross sections for the reaction gamma p -> eta-prime p have been measured with the CLAS spectrometer and a tagged photon beam with energies from 1.527 to 2.227 GeV. The results reported here possess much greater accuracy than…
A study of the partial-wave content of the $\gamma p\to \eta^\prime p$ reaction in the fourth resonance region is presented, which has been prompted by new measurements of polarization observables for that process. Using the Bonn-Gatchina…
A relativistic model for the quasifree photoproduction of eta meson from complex nuclei is developed. The interactions between fields are introduced through effective Lagrangians. Contributions from several nucleon resonances as well as…
We investigate the photoproduction of $\Lambda(1405)\equiv\Lambda^*$ hyperon resonance, i.e., $\gamma p\to K^+\Lambda^*$, employing the effective Lagrangian approach with the $t$-channel Regge trajectories at tree level. We extensively…
We examine cross sections for the processes $\gamma N\to NK\bar{K}$ in the framework of a phenomenological Lagrangian. We include contributions from $\Lambda$ and $\Sigma$ resonances up to spin 3/2, as well as those from an exotic…
We examine eta prime photoproduction, as a novel tool to study baryon resonances around 2 GeV, of particular interest to the quark shell model, which predicts a number of them. We find important roles of the form factors at the strong…
A combined analysis of photoproduction data on \gamma p to \pi N, eta N was performed including the data on K Lambda and K Sigma. The data are interpreted in an isobar model with s--channel baryon resonances and pi, rho,(omega), K, and K^*…
Total and differential cross sections for the reaction p(gamma, eta)p have been measured for photon energies in the range from 750 MeV to 3 GeV. The low-energy data are dominated by the S11 wave which has two poles in the energy region…