Search for the tri- and tetra-neutron in reactions induced by 11B and 9Be ions on 7Li

Abstract In three different heavy ion reactions the energy spectra of the 14 O, 15 O and 12 N nuclei have been measured to obtain some information about their partners in the exit channel - the multineutron systems 4 n and 3 n. No evidence for the existence of any bound state in the multineutron systems has been obtained at the cross section level of 1 nb/MeV · sr achieved in the experiment. The phase-space analysis has given no positive results concerning the existence of quasistationary states in the 4 n and 3 n systems either.