S-wave interactions of K̄ and η mesons in nuclear matter

Abstract

We give an updated discussion of the in-medium properties of K − mesons in nuclear matter, including implications for K ± subthreshold production in heavy-ion collisions. The second part of this paper focuses on s-wave interactions of η mesons in matter and the η effective mass. We point out striking differences in the in-medium behaviour of the Λ(1405) and S 11(1535) resonances. While the Λ(1405) dissolves in nuclear matter, the S 11(1535) is predicted to survive, a feature that is consistent with recent data on η photoproduction from nuclei.