Behaviour of S-Wave poles Near Threshold and the Scalar Meson Nonet Below 1 GeV
arXiv:hep-ph/0207022
Abstract
We describe the behaviour at threshold of S-wave poles of the scattering matrix within a four-parameter model for non-exotic meson-meson scattering. This model accommodates all non-exotic mesons, hence also the light scalar mesons, as resonances and bound states characterised by complex singularities of the scattering amplitude as a function of the total invariant mass. The majority of the full S-matrix mesonic poles stem from an underlying confinement spectrum. However, the light scalar mesons K0*(830), a0(980), f0(400--1200), and f0(980) do not, but instead originate in 3P0-barrier semi-bound states. We show that the behaviour of the corresponding poles is identical at threshold.
arXiv comment13 pages plain LaTeX, Contribution to 31st Int. Conf. on High Energy Physics, Amsterdam 24-31 July 2002; v2: acknowledgement and citation added