Kaon production in heavy ion collisions and kaon condensation in neutron stars

We discuss the possibility of dropping masses of kaons in dense matter. Kaon production in heavy ion collisions provide a unique environment where we can test the kaonic properties in dense system. We found that the current experiment is consistent with reduced kaon masses. This supports the idea that reduced kaon mass can soften the neutron star equation of states, reducing the maximum mass of neutron star.