Observation of Ground-State Two-Neutron Decay
  Neutron decay spectroscopy has become a successful tool to explore nuclear properties of nuclei with the largest neutron-to-proton ratios. Resonances in nuclei located beyond the neutron dripline are accessible by kinematic reconstruction of the decay products. The development of two-neutron detection capabilities of the Modular Neutron Array (MoNA) at NSCL has opened up the possibility to search for unbound nuclei which decay by the emission of two neutrons. Specifically this exotic decay mode was observed in 16Be and 26O. 
M. Thoennessen, Z. Kohley, A. Spyrou, E. Lunderberg, P. A. DeYoung, H.   Attanayake, T. Baumann, D. Bazin, B. A. Brown, G. C...
nucl-ex