First Observation of Ground State Dineutron Decay: Be-16
We report on the first observation of dineutron emission in the decay of Be-16. A single-proton knockout reaction from a 53 MeV/u B-17 beam was used to populate the ground state of Be-16. Be-16 is bound with respect to the emission of one neutron and unbound to two-neutron emission. The dineutron character of the decay is evidenced by a small emission angle between the two neutrons. The two-neutron separation energy of Be-16 was measured to be 1.35(10) MeV, in good agreement with shell model calculations, using standard interactions for this mass region.
Spyrou, A., Z. Kohley, T. Baumann, D. Bazin, B. A. Brown, G. Christian, Paul A. DeYoung, J. E. Finck, N. Frank, E. Lunderberg, S. Mosby, W. A. Peters, A. Schiller, J. K. Smith, J. Snyder, M. J. Strongman, M. Thoennessen and A. Volya. "First Observation of Ground State Dineutron Decay: Be-16." Physical Review Letters 108, no. 10.00 (2012).