Three-body analysis of incoherent eta-photoproduction on the deuteron in the near threshold region

A three-body calculation of the reaction gammad --> eta np in the energy re gion from threshold up to 30 MeV above has been performed. The primary goal of this study is to assess the importance of the three-body aspects in the hadronic sector of this reaction. Results are presented for the eta -meson spectrum as well as for the total cross section. The three-body results di ffer significantly from those predicted by a simple rescattering model in w hich only first-order etaN- and NN-interactions in the final state an consi dered. The major features of the experimental data are well reproduced alth ough right at threshold the rather large total cross section could not be e xplained. (C) 2000 Elsevier Science B.V. All rights reserved.