Correlated $\ddot{I}€\ddot{I}€$ and $K\bar{K}$ exchange in the baryon-baryon interaction

Abstract

A dynamical model for correlated two-pion and two-kaon exchange in the baryon- baryon interaction is presented, both in the scalar-isoscalar ($\ddot{I}ƒ$) and the vector-isovector ($\ddot{I}$) channel. The correlations between the two pseudoscalar mesons are taken into account by means of $\ddot{I}€\ddot{I}€-K\bar{K}$ amplitudes derived from a meson-exchange model, which is in line with the empirical $\ddot{I}€\ddot{I}€$ data. It is found that correlated $K\bar{K}$ exchange plays an important role in the $\ddot{I}ƒ$-channel for baryon-baryon states with non- vanishing strangeness. The strength of correlated $\ddot{I}€\ddot{I}€$ plus $K\bar{K}$ exchange in the $\ddot{I}ƒ$-channel decreases with the strangeness of the baryon- baryon system becoming more negative. The results for correlated $\ddot{I}€\ddot{I}€$- exchange in the vector-isovector channel deviate from what is expected in the naive SU(3) picture for genuine $\ddot{I}$-exchange. Shortcomings of a simplified description in terms of sharp mass $\ddot{I}ƒ$- and $\ddot{I}$-exchange are pointed out.

51 pages, Latex file, figures available from [email protected]