Abstract
We investigate the structure of the scalar mesons (980) and (980) within realistic meson-exchange models of the ππ and πη interactions. Starting from a modified version of the Jülich model for ππ scattering we perform an analysis of the pole structure of the resulting scattering amplitude and find, in contrast with existing models, a somewhat large mass for the (980) (=1015 MeV, =30 MeV). It is shown that our model provides a description of J/ψ→φππ/φKK data comparable in quality with those of alternative models. Furthermore, the formalism developed for the ππ system is consistently extended to the πη interaction leading to a description of the (980) as a dynamically generated threshold effect (which is therefore neither a conventional qq¯ state nor a KK¯ bound state). Exploring the corresponding pole position the (980) is found to be rather broad (=991 MeV, =202 MeV). The experimentally observed smaller width results from the influence of the nearby KK¯ threshold on this pole.
- Received 22 November 1994
DOI:https://doi.org/10.1103/PhysRevD.52.2690
©1995 American Physical Society