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Abstract: The decay of the neutron unbound ground state of 18B was studied for the first time through a single-proton knockout reaction from a 62 MeV/u 19C beam. The decay energy spectrum was reconstructed from coincidence measurements between the emitted neutron and the 17B fragment using the MoNA/Sweeper setup. An s-wave line shape was used to describe the experimental spectrum resulting in an upper limit for the scattering length of which corresponds to a decay energy <10 keV. Observing an s-wave decay of 18B provides an experimental verification that the ground state of 19C includes a large s-wave component. The presence of this s-wave component shows that s–d mixing is still present in 18B and that the orbital has not moved significantly below the orbital. [Copyright &y& Elsevier]

Abstract: The decay energy spectrum for neutron unbound states in 24O (, ) has been observed for the first time. The resonance energy of the lowest lying state, interpreted as the level, has been observed at a decay energy above 600 keV. The resulting excitation energy of the level above 4.7 MeV, supplies strong evidence that 24O is a doubly magic nucleus. The data is also consistent with the presence of a second excited state around 5.33 MeV which can be interpreted as the level. [Copyright &y& Elsevier]

Abstract: Two new neutron-deficient isotopes, 60Ge and 64Se, were observed for the first time. They were produced by projectile fragmentation of a 140-MeV/nucleon 78Kr primary beam on a beryllium target. The secondary fragments were unambiguously identified after separation in the A1900 fragment separator. The nucleus 60Ge corresponds to the heaviest isotone of the neutron shell and it is most likely the last isotone to be observed. Lower limits of 110 and 180 ns were extracted for the half-life of 60Ge and 64Se, respectively. No events of 59Ga or 63As have been observed, providing very strong evidence that these nuclei are unbound with respect to proton emission. This non-observation implies an upper limit for the half-life of 43 ns for 59Ga and 63As. [Copyright &y& Elsevier]

Two 1− levels at 5.35(10) and 6.85(5) MeV were observed for the first time in 20O. The strong direct excitation and subsequent γ-ray decay of these states in virtual photon scattering at 100 MeV/nucleon, along with B(Eλ) predictions for 20O states in this energy region, established their dipole character. The extracted B(E1)↑ values of ≃0.062(16) e2 fm2 and ≃0.035(9) e2 fm2 for the 5.35 and 6.85 MeV states, respectively, are significantly larger than shell model calculations predict. Such large dipole strengths are not observed for low-lying 1− states in 18O, indicating a shift of dipole strength towards lower energies as one approaches the neutron drip-line. [Copyright &y& Elsevier]

Abstract: First experimental evidence for a high-spin isomer () in 97Cd, a waiting point in the astrophysical rapid proton capture process, is presented. The data were obtained in β-decay studies at NSCL using the new RF Fragment Separator system and detecting β-delayed protons and β-delayed γ rays. Decays from ground and isomeric states were disentangled, and proton emission branches were determined for the first time. We find half-lives of 1.10(8) s and 3.8(2) s, and β-delayed proton emission branches of 12(2)% and 25(4)% were deduced for the ground and isomeric states, respectively. With these results, the nuclear data needed to determine an rp-process contribution to the unknown origin of solar 96Ru are in place. When the new data are included in astrophysical rp-process calculations, one finds that an rp-process origin of 96Ru is unlikely. [Copyright &y& Elsevier]

The 7Be fragments produced in one-proton removal from relativistic 8B nuclei of 936 MeV/nucleon in a carbon target have been detected in coincidence with γ rays emitted by these fragments at the reaction target. It is found that 13±3% of the 7Be fragments are released in the 429 keV excited state, 7Be&ast;, which gives direct experimental information on the ground state configuration of 8B. The longitudinal momentum distributions (p&par;) of the 7Be fragments have been measured, both inclusively and in coincidence with de-excitation γ-rays from 7Be&ast;. The widths and cross sections of the respective p&par; distributions are compared with calculations in a three-body cluster model. [Copyright &y& Elsevier]