Search

The alignment correlation terms in the β-ray angular distributions from purely spin aligned 8Li and 8B have been measured to search for the G-parity violating induced tensor term g II in the weak nucleon currents. The g II was extracted from the present alignment correlation terms, combined with the known β – α angular correlation terms and weak magnetism. This analysis permits an experimental determination of all the matrix elements necessary to extract g II . As a result, the induced tensor term was extracted as g II / g A = − 0.28 ± 0.28 (stat.) ± 0.15 (syst.) at a 1σ (68%) level. The present data and the data in the mass A = 12 and 20 systems were analyzed under the KDR model in which medium effects including the off-shell effect and meson exchange current were taken into account. We determined the 1-body contribution to be ζ = − ( 0.13 ± 0.13 ) × 10 −3 MeV −1 and the 2-body contribution to be λ = + ( 0.27 ± 0.97 ) × 10 −3 at a 1σ level.

First experimental evidence for a high-spin isomer ( 25 / 2 + ) 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.