In-gas-cell laser spectroscopy of the magnetic dipole moment of the 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>N</mml:mi><mml:mo>≈</mml:mo><mml:mn>126</mml:mn></mml:mrow></mml:math>
 isotope 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Pt</mml:mi><mml:mprescripts /><mml:none /><mml:mn>199</mml:mn></mml:mmultiscripts></mml:math>

Hirayama, Y.; Mukai, M.; Watanabe, Yutaka; Ahmed, M.; Jeong, S. C.; Jung, H. S.; Kakiguchi, Y.; Kanaya, S.; Kimura, S.; Moon, J. Y.; Nakatsukasa, Takashi; Oyaizu, M.; Park, J. H.; Schury, P.; Taniguchi, Atsuhiko; Wada, M.; Washiyama, Kouhei; Watanabe, H.; Miyatake, H.

doi:10.1103/physrevc.96.014307

Cited by 27 publications

(6 citation statements)

References 44 publications

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“…VI. The present structure agrees well with the recent observed 0.58 (8) µs isomer in 211 Tl [48], which suggests that the 17/2 + 1 state is the isomer. Our prediction on the half-life of the 17/2 + 1 state in 211 Tl is 0.66 µs, which will be shown in Sec.…”

Section: Low-lying Levelssupporting

confidence: 92%

“…The predicted half-life of the 17/2 + state in 211 Tl agrees quite well with the recently observed 0.58 (8) µs isomer [48]. Ref.…”

Section: Electric Quadrupole Propertiessupporting

confidence: 89%

“…On the neutron-rich side of the stability line in this region, the 8 + 1 seniority isomers have been observed up to 216 Pb and 210 Hg in their respective isotopic chains [4,5]. The KISS (KEK Isotope Separation System) project aims to measure the properties of the ground and isomeric states in the south region of 208 Pb [6,7], such as the magnetic moments of the ground and isomeric states of 199 Pt [8]. Reliable descriptions of the known levels and electromagnetic transition rates are necessary for a model to make new predictions in this region.…”

Section: Introductionmentioning

confidence: 99%

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Systematic shell-model study on spectroscopic properties in the south region of $^{208}$Pb

Yuan¹,

Shimizu²,

Podolyák³

et al. 2021

Preprint

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Background: The properties of nuclei located in the south region of 208 Pb are important for understanding the r-process nucleosynthesis. While some isomeric states and their spectroscopic properties have been investigated experimentally in neutron-rich Pb, Tl, and Hg isotopes recently, a large portion of the area still remains unreachable.Purpose: We aim to study the properties of nuclei in the south region of 208 Pb systematically, including the binding and excitation energies and electromagnetic properties, in order to predict unknown properties of these nuclei, such as isomerism, utilizing a theoretical model which describes the experimentally known properties precisely. We also address whether the N = 126 shell closure is robust or not when the proton number decreases from 208 Pb.Methods: We performed large-scale shell-model calculations with a new Hamiltonian suggested in the present work. The model space is taken as the five proton orbits within 50 < Z 82 and the thirteen neutron orbits within 82 < N 184. And one-particle one-hole excitation is allowed across the N = 126 gap. The Hamiltonian is constructed by combining the existing Hamiltonians, KHHE (with minor adjustment of its monopole part) and KHPE, and the monopole based universal interaction.Results: The shell-model results well reproduce the experimentally observed binding energies and spectroscopic properties, such as isomerism, core excitation, and electromagnetic properties. Some possible isomeric states in neutron-rich Pb, Tl, and Hg isotopes are predicted with transition energies and half-lives. The N = 126 shell gap is predicted to be robust from Z = 82 down to 68 with minor reduction. We also examine the effective charges and the quenching of the g factors suitable for this region by systematic comparisons between observed and calculated electromagnetic properties.Conclusions: A new Hamiltonian is constructed for nuclei in the south region of 208 Pb, which provides reasonable descriptions on various nuclear properties through comprehensive and systematic studies. The present Hamiltonian and discussions provide fruitful information for future measurements and theoretical investigations in this region, such as the recommended effective charges and g factors, the predicted binding energies, isomeric states, and core-excited states.

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Section: Low-lying Levelssupporting

confidence: 92%

“…The predicted half-life of the 17/2 + state in 211 Tl agrees quite well with the recently observed 0.58 (8) µs isomer [48]. Ref.…”

Section: Electric Quadrupole Propertiessupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Systematic shell-model study on spectroscopic properties in the south region of $^{208}$Pb

Yuan¹,

Shimizu²,

Podolyák³

et al. 2021

Preprint

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“…[160,167]. Study of neutron-rich nuclei around N=126, called ′ blank spot ′ nuclei, is in progress by multinucleon transfer reactions [168,169,170,171]. Another important nuclear physics input, the β-delayed neutron emission probability, is also under investigation in several facilities of the world [172,173,174,175,176,177].…”

Section: Discussionmentioning

confidence: 99%

“…Experimentally deduced cross sections for the production of the N=126 isotones wuth Z ≤77 are found to be much larger than those from the fragmentation experiments such as 208 Pb +Be. The MNT reactions are used to produce neutron-rich isotopes 199 Pt at the KEK Isotope Separation System (KISS), and the magnetic dipole moments and mean-square charge radius variations are measured by in-gas-cell laser ionization spectroscopy performed at KEK [169]. Spectroscopic studies of 197,198 Os and 198 Ir [170] as well as 194,196 Os [171], produced by MNT reaction at KISS, are performed to clarify the structure of these nuclei.…”

Section: β-Decay Rates For N =126 Isotones For R-process Nucleosynthesismentioning

confidence: 99%

Nuclear Weak Rates and Nuclear Weak Processes in Stars

Suzuki

2022

Preprint

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Nuclear weak rates in stellar environments are obtained by taking into account recent advances in shell-model studies of spin-dependent excitation modes in nuclei including Gamow-Teller (GT) and spin-dipole transitions. They are applied to nuclear weak processes in stars such as cooling and heating of the cores of stars and nucleosynthesis in supernovae. The important roles of accurate weak rates for the study of astrophysical processes are pointed out in the following cases. (1) The electron-capture (e-capture) and β-decay rates in sd-shell are evaluated with the USDB Hamiltonian and used to study the evolution of O-Ne-Mg cores in stars with 8-10 M ⊙ . The important roles of the A =23 and 25 pairs of nuclei for the cooling of the cores by nuclear Urca processes are investigated. (2) They are also used to study heating of the O-Ne-Mg core by double e-captures on 20 Ne in later stages of the evolution. Especially, the e-capture rates for a second-forbidden transition in 20 Ne are evaluated with the multipole expansion method by Walecka as well as the method of Behrens-Bühring. Possible important roles of the transition in heating the O-Ne-Mg cores and implications on the final fate of the cores (core-collapse or thermonuclear explosion) are discussed.(3) The weak rates in pf -shell nuclei are evaluated with a new Hamiltonian, GXPF1J, and applied to nucleosynthesis of iron-group elements in Type Ia supernova explosions. The over-production problem of neutron-rich iron isotopes compared with the solar abundances, which remained for the rates according to Fuller, Fowler and Newman, is much improved, and the over-production is now reduced to be within a factor of two. (4) The weak rates for nuclei with two-major shells are evaluated. For sd-pf shell in the island of inversion, the weak rates for the A=31 pair of nuclei, which are important for nuclear Urca processes in neutron-star crusts, are evaluated with the effective interaction obtained by the extended Kuo-Krenciglowa (EKK) method. Neutron-rich nuclei with and near neutron number (N ) of 50 are important for core-collapse processes in supernova explosions. The transition strengths and e-capture rates in 78 Ni are evaluated with a new shell-model Hamiltonian for the pf -sdg shell, and compared with those obtained by the randomphase-approximation (RPA) and an effective rate formula. (5) β-decay rates and half-lives of N =126 isotones, the waiting point nuclei for r-process nucleosynthesis, are evaluated by shell-model calculations with both the GT and first-forbidden transitions. The important roles of the forbidden transitions are pointed out for the isotones with larger proton number (Z). The half-lives are found to be shorter than those obtained by standard models such as the finite-range droplet model (FRDM) by Möller. (6) Neutrino-nucleus reaction cross sections on 13 C, 16 O and 40 Ar are obtained with new shell-model Hamiltonians. Implications on nucleosynthesis, neutrino detection, neutrino oscillations and neutrino mass hierarchy are discussed.

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