On the existence of a bound tetraneutron

Abstract

Following recent work in which events which may correspond to a bound tetraneutron (${}^4$n) were observed, it is pointed out that from the theoretical perspective the two-body nucleon-nucleon force cannot by itself bind four neutrons, even if it can bind a dineutron. A very strong phenomenological four-nucleon (4N) force is needed in order to bind the tetraneutron. Such a 4N force, if it existed, would bind ${}^4$He by about 100 MeV. Alternative experiments such as (${}^8$He,${}^4$n) are proposed to search for the tetraneutron.

Comments: 4 pages, 4 figures, submitted to Phys. Rev. C