First observation of O

Kondo, Yosuke*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; Baba, Hidetada*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.

Nature, 620(7976), p.965 - 970, 2023/08

https://doi.org/10.1038/s41586-023-06352-6

no abstracts in English

In-beam -ray spectroscopy of Mg via direct reactions

Kitamura, Noritaka*; Wimmer, K.*; Miyagi, Takayuki*; Poves, A.*; Shimizu, Noritaka*; Tostevin, J. A.*; Bader, V. M.*; Bancroft, C.*; Barofsky, D.*; Baugher, T.*; et al.

Physical Review C, 105(3), p.034318_1 - 034318_17, 2022/03

https://doi.org/10.1103/PhysRevC.105.034318

no abstracts in English

Structure of Mg explored via in-beam -ray spectroscopy

Kitamura, Noritaka*; Wimmer, K.*; Shimizu, Noritaka*; Bader, V. M.*; Bancroft, C.*; Barofsky, D.*; Baugher, T.*; Bazin, D.*; Berryman, J. S.*; Bildstein, V.*; et al.

Physical Review C, 102(5), p.054318_1 - 054318_13, 2020/11

AA2020-0765.pdf:4.4MB

https://doi.org/10.1103/PhysRevC.102.054318

no abstracts in English

Nuclear moments of the low-lying isomeric state of Al; Investigation on the neutron excitation across in the island of inversion

Xu, Z. Y.*; Heylen, H.*; Asahi, Koichiro*; Boulay, F.*; Daugas, J. M.*; de Groote, R. P.*; Gins, W.*; Kamalou, O.*; Koszors, .*; Lykiardopoupou, M.*; et al.

Physics Letters B, 782, p.619 - 626, 2018/07

AA2018-0159.pdf:0.5MB

https://doi.org/10.1016/j.physletb.2018.06.009

no abstracts in English

Low- shore of the "island of inversion" and the reduced neutron magicity toward O

Doornenbal, P.*; Scheit, H.*; Takeuchi, Satoshi*; Utsuno, Yutaka; Aoi, Nori*; Li, K.*; Matsushita, Masafumi*; Steppenbeck, D.*; Wang, H.*; Baba, Hidetada*; et al.

Physical Review C, 95(4), p.041301_1 - 041301_5, 2017/04

AA2017-0008.pdf:0.46MB

https://doi.org/10.1103/PhysRevC.95.041301

no abstracts in English

High-precision quadrupole moment reveals significant intruder component in Al ground state

Heylen, H.*; De Rydt, M.*; Neyens, G.*; Bissell, M. L.*; Caceres, L.*; Chevrier, R.*; Daugas, J. M.*; Ichikawa, Yuichi*; Ishibashi, Yoko*; Kamalou, O.*; et al.

Physical Review C, 94(3), p.034312_1 - 034312_5, 2016/09

AA2016-0115.pdf:0.4MB

https://doi.org/10.1103/PhysRevC.94.034312

no abstracts in English

Low-lying structure of Ar and the =32 subshell closure

Steppenbeck, D.*; Takeuchi, Satoshi*; Aoi, Nori*; Doornenbal, P.*; Matsushita, Masafumi*; Wang, H.*; Utsuno, Yutaka; Baba, Hidetada*; Go, Shintaro*; Lee, J.*; et al.

Physical Review Letters, 114(25), p.252501_1 - 252501_6, 2015/06

https://doi.org/10.1103/PhysRevLett.114.252501

The neutron-rich nucleus Ar is produced by the fragmentation reactions of Ca, Sc, and Ti at the RIBF facility in RIKEN, and its deexcited rays are observed for the first time. The first level in Ar is identified to lie at 1178(18)keV from the most intense -ray spectra. This experimental data, together with the systematics of the levels for surrounding nuclei, is analyzed with large-scale shell-model calculations. Consequently, the sub-shell gap in Ar is equivalent to that of Ca, thus making the level in Ar higher than that of Ar. The shell-model calculation also predicts that the sub-shell gap enhances in going from Ca to Ar, which will be verified by forthcoming experiments for Ar.

Anomalous magnetic moment of C and shell quenching in exotic nuclei

Utsuno, Yutaka

European Physical Journal A, 25(S1), p.209 - 212, 2005/09

https://doi.org/10.1140/epjad/i2005-06-088-x

no abstracts in English

Nuclidic mass formula on a spherical basis with an improved even-odd term

Koura, Hiroyuki; Tachibana, Takahiro*; Uno, Masahiro*; Yamada, Masami*

Progress of Theoretical Physics, 113(2), p.305 - 325, 2005/02

https://doi.org/10.1143/PTP.113.305

A nuclidic mass formula composed of a gross term, an even-odd term and a shell term is presented as a revised version of the mass formula constructed by the present authors and published in 2000. The gross term has almost the same functional form as in the previous formula, but the parameter values in it are somewhat different. The even-odd term is treated more carefully, and a considerable improvement is brought about. The shell term is exactly the same as the previous one; it was obtained using spherical single-particle potentials and by treating the deformed nucleus as a superposition of spherical nuclei. The new mass formula is applicable to nuclei with 1 and 1. The root-mean-square deviation from experimental masses is 0.658 MeV, which is less than that of the previous mass formula, 0.680 MeV.

Onset of intruder ground state in exotic Na isotopes and evolution of the shell gap

Utsuno, Yutaka; Otsuka, Takaharu*; Glasmacher, T.*; Mizusaki, Takahiro*; Homma, Michio*

Physical Review C, 70(4), p.044307_1 - 044307_8, 2004/10

A2004-0200.pdf:0.17MB

https://doi.org/10.1103/PhysRevC.70.044307

We perform systematic calculations of nuclear moments and energy levels in neutron-rich Na isotopes with the Monte Carlo shell model by adopting a large model space consisting of the full and part of the orbits. The calculation well reproduces those observables. The result shows that the disappearance of the magic number starts already at and that the magicity completely disappears for the isotone Na. This is in sharp contrast to previous consensus that the magic number disappears at and beyond. This early onset of disappearance indicates that the shell gap considerably narrows in Na isotopes compared to stable nuclei near Ca.