Motivated by the recently observed hypernucleus (Kiso event) 15 Ξ C ( 14 N+Ξ − ), we identify the state of this system theoretically within the framework of the relativistic-mean-field and Skyrme-Hartree-Fock models. The ΞN interactions are constructed to reproduce the two possibly observed Ξ − removal energies, 4.38 ± 0.25 MeV or 1.11 ± 0.25 MeV. The present result is preferable to be 14 N (g.s.)+Ξ − (1p), corresponding to the latter value.

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The masses of 40 neutron-rich nuclides from Z = 51 to 64 were measured at an average precision of δm/m = 10 −7 using the Canadian Penning Trap mass spectrometer at Argonne National Laboratory. The measurements, of fission fragments from a 252 Cf spontaneous fission source in a helium gas catcher, approach the predicted path of the astrophysical r process. Where overlap exists, this data set is largely consistent with previous measurements from Penning traps, storage rings, and reaction energetics, but large systematic deviations are apparent in β-endpoint measurements. Differences in mass excess from the 2003 Atomic Mass Evaluation of up to 400 keV are seen, as well as systematic disagreement with various mass models.

Relativistic mean field theory is formulated with the Green's function method in coordinate space to investigate the single-particle bound states and resonant states on the same footing. Taking the density of states for free particle as a reference, the energies and widths of single-particle resonant states are extracted from the density of states without any ambiguity. As an example, the energies and widths for single-neutron resonant states in 120 Sn are compared with those obtained by the scattering phase-shift method, the analytic continuation in the coupling constant approach, the real stabilization method and the complex scaling method. Excellent agreements are found for the energies and widths of single-neutron resonant states.

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