Dynamical coupled-channel model of kaon-hyperon interactions

The piN-->KY and KY-->KY reactions are studied using a dynamical coupled-channel model of meson-baryon interactions at energies where the baryon resonances are strongly excited. The channels included are: piN, KLambda, and KSigma. The resonances considered are: N-*[S-11(1650),P-11(1710),P-13(1720),D-13(1700)]; Delta(*)[S-31(1900),P-31(1910),P-33(1920)]; Lambda(*)[S-01(1670),P-01(1810)] Sigma(*)[P-11(1660),D-13(1670)]; and K-*(892). The basic nonresonant piN-->KY and KY-->KY transition potentials are derived from effective Lagrangians using a unitary transformation method. The dynamical coupled-channel equations are simplified by parametrizing the piN-->piN amplitudes in terms of empirical piN partial-wave amplitudes and a phenomenological off-shell function. Two models have been constructed. Model A is built by fixing all coupling constants and resonance parameters using SU(3) symmetry, the Particle Data Group values, and results from a constituent quark model. Model B is obtained by allowing most of the parameters to vary around the values of model A in fitting the data. Good fits to the available data for pi(-)p-->K(0)Lambda,K(0)Sigma(0) have been achieved. The investigated kinematics region in the center-of-mass frame goes from threshold to 2.5 GeV. The constructed models can be imbedded into associated dynamical coupled-channel studies of kaon photo- and electroproduction reactions.