In-medium Effects in the Eta-Photoproduction through the S11 Resonance with the Relativistic Approach
نویسندگان
چکیده
In-medium effects in photon excitation of the S11 resonance from nucleon and its decay to η-meson using the RMF approach is studied. We examine the in-medium effects by varing the Dirac fields of the nucleon and the S11 resonance separately. We obtained a conclusion that the Dirac fields of the nucleon, which reduces the nucleon effective mass, enlarge the width of S11 resonance, and small Dirac-fields of the resonance shifts the peak position, and these combined effects can explain the in-medium properties observed in the experimental data for C(γ,η) reaction.
منابع مشابه
In-Medium Effects in Eta Photo-production through the S11 Resonance with the Relativistic Approach
In-medium effects in photon excitation of the S11 resonance from a nucleon and its decay into an η-meson are studied using the relativistic mean field approach. We examine the inmedium effects by varying the Dirac fields of the nucleon and the S11 resonance separately. We concluse that the Dirac fields of the nucleon, which reduce the nucleon effective mass, enlarge the width of the S11 resonan...
متن کاملExtraction of the D13(1520) photon-decay couplings from pion- and eta-photoproduction data
We compare results for the D13(1520) photon-decay amplitudes determined in analyses of etaand pion-photoproduction data. The ratio of helicity amplitudes (A3/2/A1/2), determined from eta-photoproduction data, is quite different from that determined in previous analyses of pion-photoproduction data. We consider how strongly the existing pion-photoproduction data constrain both this ratio and the...
متن کاملeta photoproduction of nucleons and the structure of the resonance S11(1535) in the quark model.
In this paper, we present our study on the η photoproduction based on the chiral quark model. We find that quark model provides a very good description of the η production with much less parameters, and the threshold region is not a reliable source to determine the ηNN coupling constant due to its strong dependence on the properties of the resonance S11(1535). We suggest that the systematic dat...
متن کاملThe ηNN Coupling in Eta Photoproduction
Low-energy eta photoproduction on the nucleon is studied in an effective Lagrangian approach that contains Born terms, vector meson and nucleon resonance contributions. The resonance sector includes the S11(1535), P11(1440) and D13(1520) states whose couplings are fixed by independent electromagnetic and hadronic data. The available (γ, η) data are employed to discuss the difference between pse...
متن کاملSU(3) Chiral Dynamics with Coupled Channels: Eta and Kaon Photoproduction
We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon Lagrangian with an effective coupled-channel potential which is iterated in a Lippmann-Schwinger equation. The strangeness S = −1 resonance Λ(1405) and the S11(1535) nucleon resonance emerge as quasi-bound states of anti-kaon/nucleon and kaon/Σ-hyperon. Our approach to meson photoproduction introduces no new parameters. ...
متن کامل