First observation of the Li-13 ground state
The ground state of neutron-rich unbound Li-13 was observed for the first time in a one-proton removal reaction from Be-14 at a beam energy of 53.6 MeV/u. The Li-13 ground state was reconstructed from Li-11 and two neutrons giving a resonance energy of 120(-80)(+60) keV. All events involving single-and double-neutron interactions in the Modular Neutron Array (MoNA) were analyzed, simulated, and fitted self-consistently. The three-body (Li-11 + n + n) correlations within Jacobi coordinates showed strong dineutron characteristics. The decay energy spectrum of the intermediate Li-12 system (Li-11 + n) was described with an s-wave scattering length of greater than -4 fm, which is a smaller absolute value than reported in a previous measurement. DOI: 10.1103/PhysRevC.87.011304
Kohley, Zachary, E. Lunderberg, Paul A. De Young, Alexander Volya, Thomas Baumann, Daniel Bazin, G. Christian, N. L. Cooper, Nathan Frank, Alexandra Gade, C. Hall, Jerry Hinnefeld, Bryan A. Luther, S. Mosby, W. A. Peters, J. K. Smith, J. Snyder, Artemisia Spyrou and Michael Thoennessen. "First Observation of the Li-13 Ground State." Physical Review C 87, no. 1 (2013). http://link.aps.org/doi/10.1103/PhysRevC.87.011304.