Multi-antikaonic nuclei and in-medium kaon properties in dense matter

The effects of the Λ(1405) (Λ*) and range terms (the second-order effects, SOE) on the structure of multi-antikaonic nuclei are studied in a relativistic mean-field theory coupled with the nonlinear effective chiral Lagrangian. It is shown that, due to the attractive interaction from the Λ*-pole contribution, the K-mesons and the protons are more attracted each other than the case without the SOE. On the other hand, the density distribution for neutron is pushed outward due to the repulsive effect from the range terms. The SOE is also discussed in connection with modification of kaon properties in a dense medium.