相关论文: On Narrow Nucleon Excitation N*(1685)
We argue that the existence of a new narrow (Gamma < 25 MeV) nucleon resonance N*(1685) is strongly supported by recent data on eta photoproduction off the nucleon. The resonance has much stronger photo-coupling to the neutron than to the…
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…
Revised analysis of Sigma beam asymmetry for eta photoproduction off the free proton from GRAAL is presented. New analysis reveals a narrow structure near W ~1.685 GeV. We describe this structure by the contribution of a narrow resonance…
The recent Review of Particle Physics [1] includes a new narrow N*(1685) resonance. Its properties, the narrow width and the strong photoexcitation on the neutron, are unusual. The paper reviews experimental data which have led to the…
We briefly discuss the most recent evidences for narrow nucleon excitation with mass around 1680 MeV. The data show that the N* should have much stronger photocoupling to the neutron than to the proton. That makes it a good candidate for…
We investigate the strong and radiative decay widths of the narrow nucleon resonances $N^*(1685)$ and $N^{\ast}(1726)$ within the framework of the SU(3) chiral quark-soliton model. All the relevant parameters are taken from those used to…
Using the results of the GRAAL collaboration on the \eta photoproduction from the neutron target, we attempt to extract the partial radiative width of the possible new nucleon resonance N^*(1675). The obtained estimates support this…
The first study of quasi-free Compton scattering on the neutron in the energy range of $E_{\gamma}=0.75 - 1.5$ GeV is presented. The data reveals a narrow peak at $W\sim 1.685$ GeV. This result, being considered in conjunction with the…
We investigate the eta photoproduction using the effective Lagrangian approach at the tree level. We focus on the new nucleon resonance N*(1675), which was reported by the GRAAL, CB-ELSA and Tohoku LNS, testing its possible spin and parity…
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 ->…
New results on quasi-free $\eta$ photoproduction on the neutron and proton bound in a deuteron target are presented. The $\gamma n \to \eta n$ quasi-free cross section reveals a bump-like structure which is not seen in the cross section on…
We study a new nucleon resonance from eta photoproduction, which was observed at sqrt{s}=1675 MeV with a narrow decay width (~10 MeV) by the Tohoku LNS group as well as the GRAAL collaboration. Using an effective Lagrangian approach, we…
We present in this talk recent investigations on the nucleon-like resonance N*(1675) newly found in eta photoproduction by the GRAAL, Tohoku LNS-gamma and CB-ELSA collaborations. We focus on the production mechanism of the N*(1675),…
Revised analysis of $\Sigma$ beam asymmetry for $\eta$ photoproduction on the free proton reveals a resonant structure at $W\sim 1.69$ GeV. Comparison of experimental data with multipole decomposition based on the E429 solution of the SAID…
The recent precise experimental results for the photoproduction of $\eta$-mesons off the neutron measured with the Crystal Ball/TAPS calorimeter at the MAMI accelerator have been investigated in detail in the framework of the Bonn-Gatchina…
From the new Mainz data of eta photoproduction off protons\cite{ref1} and deuterons\cite{ref2}, we can extract, via the effective Lagrangian approach (ELA)\cite{ref3}, the electrostrong parameters $\xi_{p}$ and $\xi_{n}$ for the N$^*$(1535)…
Quasi-free photoproduction of eta-mesons off the neutron and off the proton has been studied using a deuterium target and bremsstrahlung photons produced by MAMI-C with incident energies up to 1.5 GeV. The eta-mesons were detected in…
The isobar models eta-MAID and eta'-MAID have been used to analyze new data on quasi-free eta photoproduction on the deuteron from Bonn and recent eta' data on the proton from Jlab. In eta photoproduction on the neutron a bump around W=1700…
The newest progress on the study of the strangeness in the proton and in the lowest negative parity nucleon excited state $N^*(1535)$ is reviewed. Implications on the internal quark structure of the proton, $N^*(1535)$ and other baryons are…
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^*…