2000/11/30 by F. Ritz, Frank Ritz, H. Arenhoevel +1 · 2 citations
Physics and Astronomy · #Nuclear physics research studies #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #nucl-th
paper · pdf · doi:10.1103/physrevc.64.034005
published as Phys.Rev. C64 (2001) 034005 · 24 pages of LaTeX using revtex, 23 postscript figures, few clarifying remarks and one figure added, final version accepted for publication in Phys.Rev.C
arxiv created 2001/06/08 · openalex publication_date 2001/08/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Coherent \ensuremathη-meson photoproduction on the deuteron has been studied, where the emphasis is on the relative importance of two-body contributions from hadronic rescattering and electromagnetic meson exchange currents besides the impulse approximation. For the elementary photoproduction amplitude a coupled resonance model developed by Bennhold and Tanabe has been used that fits reasonably well with the experimental data. The rescattering effects are treated within a coupled channel approach considering the intermediate excitation of the P11(1440), D13(1520), and S11(1535) nucleon resonances. The hadronic interaction between nucleon and resonances is modeled by one-boson exchange potentials, which we have considered both in the static approximation as well as fully retarded. The sum of all considered two-body effects results in an enhancement of the total cross section between 10 in the maximum and 25% closer to threshold around 680 MeV if the hadronic interaction is treated retarded. This enhancement shows up in the differential cross sections mainly at backward angles. It increases steadily from only a few percent at 0\ifmmode^∘\else\textdegree\fi to more than a factor of 2 at 180\ifmmode^∘\else\textdegree\fi for a photon energy of 680 MeV. Two-body effects also become significant in certain polarization observables. Finally, no discrepancy has been found for the ratio of the isoscalar amplitude to the proton amplitude between coherent and incoherent \ensuremathη photoproduction on the deuteron due to a nonvanishing complex and energy dependent phase relation.