In a recent experiment performed by the MoNA Collaboration at NSCL, researchers detected the heaviest oxygen isotope on record, oxygen-26. In a previous Greensheet article, it was reported that this experiment revealed that oxygen-26 is unbound with respect to the emission of two neutrons and thus decays to oxygen-24. The results were published in a recent issue of Physical Review Letters (E. Lunderberg et al., Phys. Rev. Lett. 108 (2012) 142503). Now, these results are validated in a theoretical paper in the upcoming May 7 issue of Physical Review Letters.
The new paper theoretically describes the behavior of the oxygen isotopes as they approach their limits of stability. Entitled ‘Continuum Effects and Three-nucleon forces in Neutron-rich Oxygen isotopes,’ Hagen et al. calculate that oxygen-24 is the heaviest bound oxygen isotope, in good agreement with the experimental results from MSU and other laboratories. They predict several resonances as excited states of oxygen-24, and reproduce the ground-state energies of oxygen-25 and oxygen-26.
The analysis used many-body methods, including coupled-cluster theory, along with modern supercomputing facilities, including Jaguar and Kraken housed at Oak Ridge National Laboratory and the Titan supercomputing cluster at the University of Oslo.
Combined with forthcoming experimental plans at MSU and FRIB for studies of isotope chains like neutron-rich calcium, nickel and zirconium isotopes, these results hold great promise for our basic understanding of nuclear stability.