Theoretical calculations on multi-neutron states,

Recently, peak of exstence of 4n system has been reprorted at RIKEN near 4n breakup threshold. Motived by this report, theoretical efforts have been done.

Some theoretical results are positive, that is, 4n states should be exsited as resonant state, while some results are nagative, that is, there is no resonant states.

In this workshop, I report 4n state theoretically. Also, if there is some time, I also report on 7H system.