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Zhang, W. Q.*; Andreyev, A. N.; Liu, Z.*; Seweryniak, D.*; Huang, H.*; Li, Z. H.*; Li, J. G.*; Guo, C. Y.*; 他34名*
Physics Letters B, 829, p.137129_1 - 137129_7, 2022/06
被引用回数:4 パーセンタイル:76.34(Astronomy & Astrophysics)Prompt and delayed -ray spectroscopy of the neutron-deficient, semi-magic isotope Pb has been performed at the Argonne Gas-Filled Analyzer. A new 5.15(15)-s isomeric state at only 308 keV above the spherical 3/2 ground state is identified and classified as a shape isomer. A strongly-coupled band is observed on top of the isomer, which is nearly identical to the one built on the prolate 7/2[514] Nilsson state in the isotone Hg. Based on this similarity and on the result of the potential-energy surface calculations, the new isomer in Pb is proposed to originate from the same configuration. The retarded character of the 308-keV transition can be well explained by the significant difference between the prolate parent and spherical daughter configurations, leading to the shape isomerism. The combined results of the present work and the previous -decay and laser spectroscopy studies present evidence for triple shape coexistence at low energy in the negative-parity configurations of Pb, which is well reproduced by the potential-energy surface calculations.
Barzakh, A. E.*; Atanasov, D.*; Andreyev, A. N.; Al Monthery, M.*; Althubiti, N. A.*; Andel, B.*; Antalic, S.*; Blaum, K.*; 他34名*
Physical Review C, 101(6), p.064321_1 - 064321_7, 2020/06
被引用回数:12 パーセンタイル:76.76(Physics, Nuclear)Hyperfine-structure parameters and isotope shift of the isomeric state in Au relative to Au for the 267.6-nm atomic transition have been measured for the first time using the in-source resonance-ionization spectroscopy technique. The magnetic dipole moment and change in the mean-square charge radius for this isomer have been deduced. The observed large isomer shift relative to the ground state in Au confirms the occurrence of the shape coexistence in Au proposed earlier from the analysis of the nuclear spectroscopic data and particle plus triaxial rotor calculations. The analysis of the magnetic moment supports the previously proposed , [541] assignment at moderate prolate deformation for Au.
Yang, S. B.*; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; Hwang, S.; 市川 裕大; 今井 憲一; 佐甲 博之; 佐藤 進; et al.
JPS Conference Proceedings (Internet), 17, p.012004_1 - 012004_4, 2017/07
The first -ray spectroscopy of -shell hypernucleus, F, is performed in June, 2015 at the J-PARC K1.8 beam line (J-PARC E13). Precise energy levels of F can be revealed by measured rays in this experiment. Especially, the strength of spin-spin interaction in -shell hypernucleus is obtained through the energy spacing of the ground-state doublet of the hypernucleus. By comparing its strength between the , , and -shell hypernuclei, a radial dependence interaction is investigated. The hypernucleus is produced through the reaction with the beam momentum of 1.8 GeV/c. In very preliminary results, we observed two rays, and their energies are keV and keV where the uncertainties are only statistical.
市川 裕大; 江川 弘行; 長谷川 勝一; 早川 修平; 細見 健二; 今井 憲一; 佐甲 博之; 佐藤 進; 杉村 仁志; 谷田 聖; et al.
JPS Conference Proceedings (Internet), 8, p.021020_1 - 021020_7, 2015/09
反応を用いて最も単純なK中間子原子核を探索する実験を行った。そして、世界で初めて本反応において粒子の生成領域から(1405)/(1385)粒子の生成領域までと広い質量領域での二重微分断面積を測定した。や粒子の生成領域においては2.13GeV/付近に観測したカスプ起因のピーク以外おおむね準自由過程をもとにしたシミュレーションと実験結果が一致することを確認した。一方で、の生成領域ではシミュレーションと比べて実験データのピーク位置が-24MeV/ずれていることを観測した。
杉村 仁志; 今井 憲一; 他34名*
Few-Body Systems, 54(7-10), p.1235 - 1238, 2013/08
被引用回数:0 パーセンタイル:0(Physics, Multidisciplinary)中性子過剰ハイパー核の研究はヨーロッパと日本を中心に行われている。その中で、今回J-PARCにおいて中性子過剰ハイパー核の一つであるHを生成する実験を試みた。Hは中性子4個, 陽子1個, ラムダ粒子1個からなるハイパー核で非常に陽子中性子比が大きいため、中性子過剰な中性子星の研究において大変重要な役割を果たす。そのハイパー核をJ-PARCにおいて生成し、生成断面積の上限値を与えた。