Radial excitations of low-lying baryons and the Z+ penta-quark
Institute for Theoretical Physics, Tübingen University, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
Received: 20 April 1998 / Revised version: 29 May 1998 Communicated by F. Lenz
Within an extended Skyrme soliton model for baryons the interplay between the collective radial motion and the SU(3)-flavor-rotations is investigated. The coupling between these modes is mediated by flavor symmetry breaking. Collective coordinates which describe the corresponding large amplitude fluctuations are introduced and treated canonically. When diagonalizing the resulting Hamiltonian flavor symmetry breaking is fully taken into consideration. As eigenstates not only the low-lying and baryons but also their radial excitations are obtained and compared to the empirical data. In particular the relevance of radial excitations for the penta-quark baryon Z+ (Y=2, I=0, ) is discussed. In this approach its mass is predicted to be . Furthermore the widths for various hadronic decays are estimated which, for example, yields for the only permissible decay process of the Z+.
12.39.Dc Skyrmions - 14.20.Gk Baryon resonances with S=0 - 14.20.Jn. Hyperons