IKEDA, the partner for exploring the nuclear highland far from the valley of stability

I have been collaborating with Ikeda since 1980’s when I started the experiment with radioactive nuclear beams. He has been interested in explaining the halo structure and binding energy of 11Li from the very beginning. From these studies, new basic concepts have been introduced, one of such important ideas is the soft resonance and cluster structure of halo nuclei. He also introduced the importance of the tensor forces on the halo formation, in particular for the correlation of two halo neutrons though s- and p- wave mixing. As an experimentalist, I have been trying to provide data to help him to develop these ideas. Here, I present the recent progresses in experimental studies. One is the first measurement of the two-neutron transfer reaction of 11Li to study the correlation between two halo neutrons. The other is a new on going experiment to obtain the direct evidence of the tensor forces in nuclei.