Analysis of the low-energy NN-dynamics within a three-body formalism
1 Tomsk Polytechnic University, 634034 Tomsk, Russia
2 Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
Received: 27 June 2000
Communicated by W. Weise
The interaction of an -meson with two nucleons is studied within a three-body approach. The major features of the -system in the low-energy region are accounted for by using a s-wave separable ansatz for the two-body and NN amplitudes. The calculation is confined to the and (1-;0)configurations which are assumed to be the most promising candidates for virtual or resonant -states. The eigenvalue three-body equation is continued analytically into the nonphysical sheets by contour deformation. The position of the poles of the three-body scattering matrix as a function of the -interaction strength is investigated. The corresponding trajectory, starting on the physical sheet, moves around the three-body threshold and continues away from the physical area giving rise to virtual -states. The search for poles on the nonphysical sheets adjacent directly to the upper rim of the real energy axis gives a negative result. Thus no low-lying s-wave -resonances were found. The possible influence of virtual poles on the low-energy -scattering is discussed.
13.60.Le Meson production - 21.45.+v Few-body systems - 25.20.Lj Photoproduction reactions
Copyright Società Italiana di Fisica, Springer-Verlag 2000