16 research outputs found
Spectroscopy of 32Ne and the Island of Inversion
We report on the first spectroscopic study of the N=22 nucleus 32Ne at the
newly completed RIKEN Radioactive Ion Beam Factory. A single gamma-ray line
with an energy of 722(9) keV was observed in both inelastic scattering of a 226
MeV/u 32Ne beam on a Carbon target and proton removal from 33Na at 245 MeV/u.
This transition is assigned to the de-excitation of the first J^pi = 2+ state
in 32Ne to the 0+ ground state. Interpreted through comparison with
state-of-the-art shell model calculations, the low excitation energy
demonstrates that the Island of Inversion extends to at least N=22 for the Ne
isotopes.Comment: Accepted for publication in Phys. Rev. Lett. 11 pages, 3 figure
Half-life measurement of stored fully ionized and hydrogen-like 122I ions
The half-lives of fully ionized and hydrogen-like (H-like) 122I ions have been measured in a
heavy-ion storage ring. The \u3b2+-decay constants for both charge states and the electron capture (EC)
decay constant of H-like ions have been determined. The EC-decay constant in H-like 122I ions \u3bbH-like
EC =
7.35(33) \ub7 10 124 s 121 is, within the uncertainty, the same as the one in neutral atoms. This result is in
agreement with the estimates of recent theoretical considerations on the EC-decay of few-electron ions that
explicitly take into account the conservation of the total angular momentum of the nucleus plus lepton(s)
system and its projections. No firm confirmation could be concluded from our results on the predicted effect
that allowed Gamow-Teller transitions become forbidden if the initial and final total angular momenta are
not equal
Half-life measurements of stored fully ionized and hydrogen-like I-122 ions
International audienceThe half-lives of fully ionized and hydrogen-like (H-like) I-122 ions have been measured in a heavy-ion storage ring. The beta(+)-decay constants for both charge states and the electron capture (EC) decay constant of H-like ions have been determined. The EC-decay constant in H-like I-122 ions lambda(H-like)(EC) = 7.35(33) . 10(-4) s(-1) is, within the uncertainty, the same as the one in neutral atoms. This result is in agreement with the estimates of recent theoretical considerations on the EC-decay of few-electron ions that explicitly take into account the conservation of the total angular momentum of the nucleus plus lepton(s) system and its projections. No firm confirmation could be concluded from our results on the predicted effect that allowed Gamow-Teller transitions become forbidden if the initial and final total angular momenta are not equal
Charge-changing interactions probing point-proton radii of nuclei
The question of whether charge-changing interactions can be used to probe point-proton radii of nuclei remains unanswered. Charge-changing cross sections, Ïcc, were systematically investigated using stable and unstable nuclear beams of intermediateenergy. The ratios of the experimental Ïcc values to the calculated ones obtained from a phenomenological Glauber-type model analysis are found to be nearly constant in a broad range of Z/N for light neutron-rich nuclei. This enables the determination of density distributions, i.e., the radii of protons tightly bound in nuclei. To test the applicability of the present method to all nuclei in the nuclear chart, extensive measurements were performed for medium-mass nuclei ranging from Z = 18 to 32. The present study suggests the potential capability of a new experimental approach for exploring exotic nuclei
Charge-changing interactions probing point-proton radii of nuclei
The question of whether charge-changing interactions can be used to probe point-proton radii of nuclei remains unanswered. Charge-changing cross sections, Ïcc, were systematically investigated using stable and unstable nuclear beams of intermediateenergy. The ratios of the experimental Ïcc values to the calculated ones obtained from a phenomenological Glauber-type model analysis are found to be nearly constant in a broad range of Z/N for light neutron-rich nuclei. This enables the determination of density distributions, i.e., the radii of protons tightly bound in nuclei. To test the applicability of the present method to all nuclei in the nuclear chart, extensive measurements were performed for medium-mass nuclei ranging from Z = 18 to 32. The present study suggests the potential capability of a new experimental approach for exploring exotic nuclei
Charge-changing cross sections of , with a proton target
The total charge-changing, charge pick-up, and partial charge-changing cross sections of very neutron-rich nuclei (^<30>Ne, ^<32,33>Na) with a proton target have been measured at âŒ240A MeV for the first time. We introduced the phenomenological correction factor in Glauber-model calculations for the total charge-changing cross sections with the proton target, and applied it to deduce the proton radii of these nuclei. For ^<30>Ne and ^<32>Na, the neutron skin thicknesses of the nuclei were deduced by comparing the proton radii with the matter radii deduced from the interaction cross-section measurements. A significant thick neutron-skin has been observed for the nuclei. We also found that the charge pick-up cross sections are much larger than those in the systematics of stable nuclei