Exclusive measurement of quasi-free η-photoproduction from deuterium

+eta+n+p%22&type=SU">photon deuteron --> eta n p, Recoil, 0103 physical sciences, ddc:530, recoil [nucleon], Neutron, Nuclear Experiment (nucl-ex), ratio [channel cross section], spectator [model], Nuclear Experiment, 010306 general physics, Microtron, QC, Physics, photoproduction [eta], 010308 nuclear & particles physics, multiple scattering, photon deuteron --> eta anything, angular dependence, Deuterium, interaction [photon deuteron], High Energy Physics::Experiment, Atomic physics, Nucleon -->
Popis: Quasi-free photoproduction of eta-mesons from the deuteron has been measured at the tagged photon facility of the Mainz microtron MAMI with the photon spectrometer TAPS for incident photon energies from the production threshold at 630 MeV up to 820 MeV. In a fully exclusive measurement eta-mesons and recoil nucleons were detected in coincidence. At incident photon energies above the production threshold on the free nucleon, where final state interaction effects are negligible, an almost constant ratio of sigma(n)/sigma(p)=0.66+/-0.10 was found. At lower incident photon energies the ratio rises due to re-scattering effects. The average ratio agrees with the value extracted from a comparison of the inclusive d(gamma,eta)X cross section to the free proton cross section via a participant - spectator model for the deuteron cross section (sigma(n)/sigma(p)=0.67+/-0.07). The angular dependence of the ratio agrees with the expected small deviation of neutron and proton cross section from isotropy due to the influence of the D13(1520) resonance. The energy dependence of the ratio in the excitation energy range of the S11(1535) resonance disfavors model predictions which try to explain this resonance as K-Sigma bound state.
Comment: 10 pages, 9 figures, Eur. Phys. Journal A, accepted
Popis souboru: text/html
ISSN: 1434-601X
1434-6001
DOI: 10.1140/epja/i2002-10085-9
Přístupová URL adresa: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2f02044464354de67ca79835524ea698
https://doi.org/10.1140/epja/i2002-10085-9
Rights: OPEN
Přírůstkové číslo: edsair.doi.dedup.....2f02044464354de67ca79835524ea698
Autor: M. Kotulla, M. Wolf, V. Kuhr, A. Schmidt, B. Krusche, F. Wissmann, R. Beck, J. Weiß, R. Leukel, R.O. Owens, U. Siodlaczek, F. Rambo, V. Kleber, H. Ströher, V. Metag, V. Hejny, P. Achenbach, V. Olmos de León
Rok vydání: 2003
Předmět:
Zdroj: The European physical journal / A 16, 275-284 (2003). doi:10.1140/epja/i2002-10085-9
ISSN: 1434-601X
1434-6001
DOI: 10.1140/epja/i2002-10085-9
Popis: Quasi-free photoproduction of eta-mesons from the deuteron has been measured at the tagged photon facility of the Mainz microtron MAMI with the photon spectrometer TAPS for incident photon energies from the production threshold at 630 MeV up to 820 MeV. In a fully exclusive measurement eta-mesons and recoil nucleons were detected in coincidence. At incident photon energies above the production threshold on the free nucleon, where final state interaction effects are negligible, an almost constant ratio of sigma(n)/sigma(p)=0.66+/-0.10 was found. At lower incident photon energies the ratio rises due to re-scattering effects. The average ratio agrees with the value extracted from a comparison of the inclusive d(gamma,eta)X cross section to the free proton cross section via a participant - spectator model for the deuteron cross section (sigma(n)/sigma(p)=0.67+/-0.07). The angular dependence of the ratio agrees with the expected small deviation of neutron and proton cross section from isotropy due to the influence of the D13(1520) resonance. The energy dependence of the ratio in the excitation energy range of the S11(1535) resonance disfavors model predictions which try to explain this resonance as K-Sigma bound state.
Comment: 10 pages, 9 figures, Eur. Phys. Journal A, accepted
Databáze: OpenAIRE
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