K + mesons, a robust probe to measure the hadronic equation of state?

We demonstrate that the K + mesons are sensitive to nuclear matter properties, especially to the hadronic equation of state (EoS). Once one has understood how K + behave in hadronic matter we can use these mesons to study the hadronic EoS. Several observables point towards a rather soft EoS at densities around three times the normal nuclear matter density ρ0.