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New level structures are proposed for neutron-rich 127,129,131In populated in the decay of 127,129,131Cd. No evidence for the presence of 1-particle-2-hole intruder structures in the neutron-rich In isotopes is observed. [ABSTRACT FROM AUTHOR]

Despite a lot of experimental and theoretical progress the question of the r-process site and the origin of the heavy elements in nature remains one of the biggest open questions in nuclear astrophysics. We report first results from experiments with rare isotope beams of r-process nuclei at Michigan State University’s National Superconducting Cyclotron Laboratory. This includes a first measurement of the half-life of the doubly-magic waiting point nucleus 78Ni, which serves as a major bottle-neck for the synthesis of heavy elements in many r-process models. [ABSTRACT FROM AUTHOR]

The low energy level structure of neutron-rich 28, 29Na has been investigated through β-delayed γ spectroscopy. The present work, which presents the first detailed spectroscopy of 29Na, clearly demonstrates that for Na isotopes between 28Na ( N = 17) and 29Na ( N = 18), intruder configurations start dominating the low lying excited states, suggestive of the small N = 20 shell gap. [ABSTRACT FROM AUTHOR]

The low-energy level structure of the exotic Na isotopes (28,29)Na has been investigated through beta-delayed gamma spectroscopy. The N=20 isotones for Z=10-12 are considered to belong to the "island of inversion" where intruder configurations dominate the ground state wave function. However, it is an open question as to where and how the transition from normal to intruder dominated configurations happens in an isotopic chain. The present work, which presents the first detailed spectroscopy of (28,29)Na, clearly demonstrates that such a transition in the Na isotopes occurs between 28Na (N=17) and 29Na (N=18), supporting the smaller N=20 shell gap in neutron-rich sd shell nuclei. The evidence for inverted shell structure is found in beta-decay branching ratios, intruder dominated spectroscopy of low-lying states, and shell model analysis.

Recent experimental characterization of the subshell closure at N=32 in the Ca, Ti, and Cr isotones has stimulated shell-model calculations that indicated the possibility that the N=34 isotones of these same elements could exhibit characteristics of a shell closure, namely, a high energy for the first excited 2(+) level. To that end, we have studied the decay of 56Sc produced in fragmentation reactions and identified new gamma rays in the daughter N=34 isotone 56Ti. The first 2(+) level is found at an energy of 1127 keV, well below the expected position that would indicate the presence of an N=34 shell closure in 56Ti.

Spin polarization of 37K nuclei produced via single proton pickup from a 9Be target by a beam of 150 MeV/nucleon 36Ar has been observed. Positive spin polarization with magnitude (8.5+/-0.6)% was deduced near the peak of the 37K momentum distribution. The variation of the spin polarization as a function of outgoing 37K momentum is explained by a classical conservation model, as previously applied to describe the induced spin polarization observed for fragments produced in intermediate-energy heavy-ion reactions, with the condition that the picked-up proton has an average momentum equal to the Fermi momentum and is aligned along the incident beam direction.