Pauli-Principle Driven Correlations in Four-Neutron Nuclear Decays

Mechanism of simultaneous non-sequential four-neutron (4 n ) emission (or “true” 4 n -decay) has been considered in phenomenological five-body approach. This approach is analogous to the model of the direct decay to the continuum often applied to 2 n - and 2 p -decays. It is demonstrated that 4 n -decay fragments should have specific energy and angular correlations reflecting strong spatial correlations of “valence” nucleons orbiting in their 4 n -precursors. Due to the Pauli exclusion principle, the valence neutrons are pushed to the symmetry-allowed configurations in the 4 n -precursor structure, which causes a “Pauli focusing” effect. Prospects of the observation of the Pauli focusing have been considered for the 4 n -precursors 7 H and 28 O. Fingerprints of their nuclear structure or/and decay dynamics are predicted.