Resonances and the Weinberg-Tomozawa 56-baryon-35-meson interaction
Departamento de Fısica Atómica, Molecular y Nuclear, Universidad de Granada, E-18071, Granada, Spain
Accepted: 1 November 2006
Published online: 22 February 2007
Vector meson degrees of freedom are incorporated into the Weinberg-Tomozawa (WT) meson-baryon chiral Lagrangian by using a scheme which relies on spin-flavor SU(6) symmetry. The corresponding Bethe-Salpeter approximation successfully reproduces previous SU(3)-flavor WT results for the lowest-lying s-wave negative-parity baryon resonances, and it also provides some information on the dynamics of the heavier ones. Moreover, it also predicts the existence of an isoscalar spin-parity - K*N bound state (strangeness +1) with a mass around 1.7-1.8GeV, unstable through K* decay. Neglecting d-wave KN decays, this state turns out to be quite narrow ( Γ≤15MeV) and it might provide clear signals in reactions like γp→¯0 pK + π - by looking at the three-body pK + π - invariant mass.
PACS: 11.30.Hv Flavor symmetries – / 11.10.St Bound and unstable states; Bethe-Salpeter equations – / 11.30.Rd Chiral symmetries – / 11.80.Gw Multichannel scattering –
© Società Italiana di Fisica and Springer-Verlag, 2007