The influence of KD and K anti K mesonic molecules in selected reactions

The attractive potential of the Juelich meson exchange model in the K anti K-channel causes formation of a scalar isoscalar molecule. We investigate this observation from different points of view. First we look at the dependence of pion production in the peripheral reaction π-p → π0π0n on the momentum transferred at the nucleus. Accounting for the production via π and a1 emission in a consistent way, we are able to explain the momentum dependence using the Juelich model. Furthermore we investigate how a measurement of dd → αK anti K close to threshold may contribute to our knowledge on K anti K interaction and the f0(980). The Juelich model links the properties of the f0(980) to the a0(980). We will use this information to learn about the d anti K-interaction in pp → dK anti K. The recent discovery of the D*sJ(2317) o ers a different perspective on the dynamical generation of poles, since it may be connected to the KD-threshold nearby. We construct a SU(4)-extention of the Juelich model including isospin violation. Within this extention a dynamical resonance is formed, which only may explain the D*sJ(2317) if isoscalar production is assumed. Special interest is paid to the predicted width of the D*sJ(2317) associated with a dynamical interpretation. (orig.)