Chiral dynamics in systems with strangeness

Abstract

In this talk a brief review of several problems involving systems with strangeness is made. In the first place one shows how the $\Lambda (1405)$, $\Lambda (1670)$ and $\Sigma (1620)$ states, for $S=-1$, and the $\Xi (1620)$ for $S=-2$ are generated dynamically in the context of unitarized chiral perturbation theory. The results for the $\bar{K}N$ interaction are then used to evaluate the $K^{-}d$ scattering length. Results obtained for the kaon selfenergy in a nuclear medium within this approach, with application to $K^{-}$ atoms, are also mentioned. Finally a few words are said about recent developments in the weak decay of $\Lambda$ hypernuclei and the puzzle of the ${\Gamma }_n/{\Gamma }_p$ ratio.

Talk in the XVIII European Few Body Conference, Bled, Slovenia, September 2002