JAEA
  • help
  • PC | SP
  • JP | EN
          
検索対象：     
報告書番号：
※ 半角英数字
 年 ～ 
 年
全てクリア
検索結果：　41 件中 1件目～20件目を表示

発表形式

Initialising ...

選択項目を絞り込む

掲載資料名

Initialising ...

発表会議名

Initialising ...

筆頭著者名

Initialising ...

キーワード

Initialising ...

使用言語

Initialising ...

発行年

Initialising ...

開催年

Initialising ...

選択した検索結果をダウンロード

論文

First observation of the decay of the 13/2$$^+$$ isomer in $$^{183}$$Hg and $$B$$(${it M}$2) systematics of neutron transitions across the nuclear chart

Huang, H.*; Zhang, W. Q.*; Andreyev, A. N.; Liu, Z.*; Seweryniak, D.*; Li, Z. H.*; Guo, C. Y.*; Barzakh, A. E.*; Van Duppen, P.*; Andel, B.*; et al.

Physics Letters B, 833, p.137345_1 - 137345_8, 2022/10

https://doi.org/10.1016/j.physletb.2022.137345
 被引用回数：0 パーセンタイル：0.02(Astronomy & Astrophysics)

The decay of the 13/2$$^+$$ isomeric state in $$^{183}$$Hg was observed for the first time following the $$alpha$$ decay of the 13/2$$^+$$ isomer in $$^{187}$$Pb produced in the $$^{142}$$Nd$$(^{50}$$Cr$$, 2p3n)$$ reaction. Using $$alpha$$-$$gamma$$ delayed coincidence measurements, the half-life of this isomer was measured to be 290(30) $$mu$$s. This isomer is proposed to deexcite by an unobserved low-energy $$M$$2 transition to the known 9/2$$^-$$ member of a strongly prolate-deformed 7/2$$^-$$[514] band, followed by a 105-keV $$M$$1 transition to the bandhead. A lower limit of B($$M$$2)$$geq$$0.018 W.u. was deduced for the unobserved transition. The presumed retardation is proposed to be due to the notable shape change between the initial, nearly spherical, and the final, strongly deformed, states. A similar scenario is also considered for the 13/2$$^+$$ isomer in $$^{181}$$Hg, suggesting both are cases of shape isomers. The B($$M$$2) systematics of neutron transitions across the nuclear chart is discussed.

論文

New $$beta$$-decaying state in $$^{214}$$Bi

Andel, B.*; Van Duppen, P.*; Andreyev, A. N.; Blazhev, A.*; Grawe, H.*; Lica, R.*; Na$"i$dja, H.*; Stryjczyk, M.*; 他52名*

Physical Review C, 104(5), p.054301_1 - 054301_13, 2021/11

https://doi.org/10.1103/PhysRevC.104.054301
 被引用回数：1 パーセンタイル：18.91(Physics, Nuclear)

A new $$beta$$-decaying state in $$^{214}$$Bi has been identified at the ISOLDE Decay Station at the CERN-ISOLDE facility. A preferred $$I^{pi} = (8^{-})$$ assignment was suggested for this state based on the $$beta$$-decay feeding pattern to levels in $$^{214}$$Po and shell-model calculations. The half-life of the $$I^{pi} = (8^{-})$$ state was deduced to be $$T_{1/2} = 9.39 (10)$$ min. The deexcitation of the levels populated in $$^{214}$$Po by the $$beta$$ decay of this state was investigated via $$gamma-gamma$$ coincidences and a number of new levels and transitions were identified. Shell-model calculations for excited states in $$^{214}$$Bi and $$^{214}$$Po were performed using two different effective interactions: the H208 and the modified Kuo-Herling particle interaction. Both calculations agree on the interpretation of the new $$beta$$-decaying state as an $$I^{pi} = 8^{-}$$ isomer and allow for the tentative assignment of shell-model states to several high-spin states in $$^{214}$$Po.

論文

Laser-assisted nuclear decay spectroscopy of $$^{176,177,179}$$Au

Harding, R. D.*; Andreyev, A. N.; Barzakh, A. E.*; Cubiss, J. G.*; Van Duppen, P.*; Al Monthery, M.*; Althubiti, N. A.*; Andel, B.*; 他26名*

Physical Review C, 104(2), p.024326_1 - 024326_16, 2021/08

https://doi.org/10.1103/PhysRevC.104.024326
 被引用回数：5 パーセンタイル：46.8(Physics, Nuclear)

A detailed nuclear spectroscopy study of $$^{176,177,179}$$Au was performed at ISOLDE, CERN. This work provides new insights into the low-lying levels in the daughter nuclei $$^{172,173,175}$$Ir. For $$^{176}$$Au, the nuclear magnetic moments of a high spin and low spin state were determined and used to predict the most likely configuration of each level. Their $$alpha$$-decay branching ratios were also extracted: a 58(5)% branching for the low-spin state, and 29(5)% for the high-spin state.

論文

Competition between allowed and first-forbidden $$beta$$ decays of $$^{208}$$At and expansion of the $$^{208}$$Po level scheme

Brunet, M.*; Podoly$'a$k, Zs.*; Berry, T. A.*; Brown, B. A.*; Carroll, R. J.*; Lica, R.*; Sotty, Ch.*; Andreyev, A. N.; Borge, M. J. G.*; Cubiss, J. G.*; et al.

Physical Review C, 103(5), p.054327_1 - 054327_13, 2021/05

https://doi.org/10.1103/PhysRevC.103.054327
 被引用回数：4 パーセンタイル：57.13(Physics, Nuclear)

The structure of $$^{208}$$Po populated through the EC/$$beta^{+}$$ decay of $$^{208}$$At is investigated using $$gamma$$-ray spectroscopy at the ISOLDE Decay Station. The presented level scheme contains 27 new excited states and 43 new transitions, as well as a further 50 previously observed $$gamma$$ rays which have been (re)assigned a position. Through the analysis using the shell model calculations approximately half of the $$beta$$-decay strength of $$^{208}$$At is found to proceed via allowed decay and half via first-forbidden decay. The first-forbidden transitions predominantly populate core excited states at high excitation energies, which is qualitatively understood using shell model considerations.

論文

Laser-assisted decay spectroscopy for the ground states of $$^{180,182}$$Au

Harding, R. D.*; Andreyev, A. N.; Barzakh, A. E.*; Atanasov, D.*; Cubiss, J. G.*; Van Duppen, P.*; 他40名*

Physical Review C, 102(2), p.024312_1 - 024312_16, 2020/08

https://doi.org/10.1103/PhysRevC.102.024312
 被引用回数：10 パーセンタイル：73.66(Physics, Nuclear)

A detailed nuclear spectroscopy study of $$^{180}$$Au was performed. An $$alpha$$-decay branching ratio of $$0.58(10)$$% and a half-life of $$7.2(5)$$s have been derived. The first measurement of the hyper fine structure for atomic transitions has been also performed, from which the magnetic dipole moment has been extracted. A spin assignment of $$(1^+)$$ is proposed for the ground state of $$^{180}$$Au, with a $$(pi3/2^-$$[532]$$timesnu5/2^-$$[512]$$)$$ configuration.

論文

$$alpha$$-decay branching ratio of $$^{180}$$Pt

Cubiss, J. G.*; Harding, R. D.*; Andreyev, A. N.; Althubiti, N.*; Andel, B.*; Antalic, S.*; Barzakh, A. E.*; Cocolios, T. E.*; Day Goodacre, T.*; Farooq-Smith, G. J.*; et al.

Physical Review C, 101(1), p.014314_1 - 014314_4, 2020/01

https://doi.org/10.1103/PhysRevC.101.014314
 被引用回数：5 パーセンタイル：52.72(Physics, Nuclear)

$$^{180}$$Ptの基底状態から娘核$$^{176}$$Osの基底状態への$$alpha$$崩壊分岐比を0.52(5)%と、過去の値と比較してより高精度で再決定した。$$^{180}$$PtはCERN-ISOLDE実験施設において$$^{180}$$Hgを単離し、その$$beta$$崩壊孫核種として生成した。今回の結果を用いて導出した$$alpha$$崩壊の換算崩壊幅は、中性子欠損Pt同位体の$$alpha$$崩壊幅の系統性について新しい描像を与えることとなった。

論文

$$alpha$$-decay properties of $$^{200,202}$$Fr

Ghys, L.*; Andreyev, A. N.; Huyse, M.*; Van Duppen, P.*; Antalic, S.*; Barzakh, A.*; Capponi, L.*; Cocolios, T. E.*; Cubiss, J.*; Derkx, X.*; et al.

Physical Review C, 100(5), p.054310_1 - 054310_13, 2019/11

https://doi.org/10.1103/PhysRevC.100.054310
 被引用回数：12 パーセンタイル：77.09(Physics, Nuclear)

The aim of this work was to investigate the $$alpha$$-decay properties of $$^{200,202}$$Fr and daughter products. Neutron-deficient francium nuclei are produced at ISOLDE-CERN bombarding a UCx target with 1.4 GeV protons. Due to the very high statistics and the high beam purity, improved decay data for $$^{202}$$Fr and its daughters were obtained. The observation of crossover transitions positioned the isomeric high-spin level of $$^{198}$$At at an excitation energy of 265(3) keV. Half-life values of 4.47(5) s and 1.28(10) s were extracted for the ground state and isomeric state of $$^{198}$$At and 52(3) ms for the ground-state decay of $$^{200}$$Fr.

論文

Electromagnetic properties of low-lying states in neutron-deficient Hg isotopes; Coulomb excitation of $$^{182}$$Hg, $$^{184}$$Hg, $$^{186}$$Hg and $$^{188}$$Hg

Wrzosek-Lipska, K.*; Rezynkina, K.*; Bree, N.*; Zieli$'n$ska, M.*; Gaffney, L. P.*; Petts, A.*; Andreyev, A. N.; Bastin, B.*; Bender, M.*; Blazhev, A.*; et al.

European Physical Journal A, 55(8), p.130_1 - 130_23, 2019/08

https://doi.org/10.1140/epja/i2019-12815-2
 被引用回数：11 パーセンタイル：74.44(Physics, Nuclear)

The neutron-deficient mercury isotopes serve as a classical example of shape coexistence, whereby at low energy near-degenerate nuclear states characterized by different shapes appear. The electromagnetic structure of even-mass $$^{182-188}$$Hg isotopes was studied using safe-energy Coulomb excitation of neutron-deficient mercury beams delivered by the REX-ISOLDE facility at CERN. The population of 0$$^{+}_{1,2}$$, 2$$^{+}_{1,2}$$, and 4$$^{+}_{1}$$ states was observed in all nuclei under study. Reduced $$E2$$ matrix elements coupling populated yrast and non-yrast states were extracted, including their relative signs. These are a sensitive probe of shape coexistence and may be used to validate nuclear models. The experimental results are discussed in terms of mixing of two different configurations and are compared with three different model calculations: the Beyond Mean Field model, the Interacting Boson Model with configuration mixing and the General Bohr Hamiltonian. Partial agreement with experiment was observed, hinting to missing ingredients in the theoretical descriptions.

論文

Fine structure in the $$alpha$$ decay of $$^{218}$$At

Cubiss, J. G.*; Andreyev, A. N.; Barzakh, A. E.*; Andel, B.*; Antalic, S.*; Cocolios, T. E.*; Day Goodacre, T.*; Fedorov, D. V.*; Fedosseev, V. N.*; Ferrer, R.*; et al.

Physical Review C, 99(6), p.064317_1 - 064317_6, 2019/06

https://doi.org/10.1103/PhysRevC.99.064317
 被引用回数：6 パーセンタイル：53.97(Physics, Nuclear)

$$^{218}$$Atの$$alpha$$崩壊について、CERN-ISOLDE施設においてレーザーイオン化法を使うことで研究した。$$alpha$$-$$gamma$$同時計数データを初めて取得し、より精度の良い半減期の値として1.27(6)秒を得た。$$alpha$$崩壊の微細構造を基に新しい$$alpha$$崩壊図式を構築した。それらの結果から、$$^{218}$$Atの基底状態のスピン・パリティは(3$$^{-}$$)がより確からしいことが解ったが、(2)$$^{-}$$の可能性も完全には否定しきれない。

論文

Investigation of the $$Delta$$$$n$$ = 0 selection rule in Gamow-Teller transitions; The $$beta$$-decay of $$^{207}$$Hg

Berry, T. A.*; Podoly$'a$k, Zs.*; Carroll, R. J.*; Lic$u{a}$, R.*; Grawe, H.*; Timofeyuk, N. K.*; Alexander, T.*; Andreyev, A. N.; Ansari, S.*; Borge, M. J. G.*; et al.

Physics Letters B, 793, p.271 - 275, 2019/06

https://doi.org/10.1016/j.physletb.2019.04.039
 被引用回数：5 パーセンタイル：47.88(Astronomy & Astrophysics)

Gamow-Teller $$beta$$ decay is forbidden if the number of nodes in the radial wave functions of the initial and final states is different. This $$Delta$$$$n$$ = 0 requirement plays a major role in the $$beta$$ decay of heavy neutron-rich nuclei, affecting the nucleosynthesis through the increased half-lives of nuclei on the astrophysical $$r$$-process pathway below both $$Z$$ = 50 (for $$N >$$ 82) and $$Z$$ = 82 (for $$N >$$ 126). The level of forbiddenness of the $$Delta$$$$n$$ = 1 $$nu$$1$$g_{9/2} rightarrow pi$$0$$g_{7/2}$$ transition has been investigated from the $$beta^{-}$$ decay of the ground state of $$^{207}$$Hg into the single-proton-hole nucleus $$^{207}$$Tl in an experiment at the ISOLDE Decay Station. From statistical observational limits on possible $$gamma$$-ray transitions depopulating the $$pi$$0$$g^{-1}_{7/2}$$ state in $$^{207}$$Tl, an upper limit of 3.9$$times$$10$$^{-3}$$ % was obtained for the probability of this decay, corresponding to log$$ft >$$ 8.8 within a 95% confidence limit. This is the most stringent test of the $$Delta$$$$n$$ = 0 selection rule to date.

論文

Inverse odd-even staggering in nuclear charge radii and possible octupole collectivity in $$^{217,218,219}$$At revealed by in-source laser spectroscopy

Barzakh, A. E.*; Cubiss, J. G.*; Andreyev, A. N.; Seliverstov, M. D.*; Andel, B.*; Antalic, S.*; Ascher, P.*; Atanasov, D.*; Beck, D.*; Biero$'n$, J.*; et al.

Physical Review C, 99(5), p.054317_1 - 054317_9, 2019/05

https://doi.org/10.1103/PhysRevC.99.054317
 被引用回数：12 パーセンタイル：77.09(Physics, Nuclear)

Hyperfine-structure parameters and isotope shifts for the 795-nm atomic transitions in $$^{217,218,219}$$At have been measured at CERN-ISOLDE, using the in-source resonance-ionization spectroscopy technique. Magnetic dipole and electric quadrupole moments, and changes in the nuclear mean-square charge radii, have been deduced. A large inverse odd-even staggering in radii, which may be associated with the presence of octupole collectivity, has been observed. Namely, the radius of the odd-odd isotope $$^{218}$$At has been found to be larger than the average.

論文

Alpha decay and beta-delayed fission; Tools for nuclear physics studies

Van Duppen, P.*; Andreyev, A. N.

The Euroschool of Exotic Beams, Vol.5, p.65 - 116, 2018/04

https://doi.org/10.1007/978-3-319-74878-8_3

$$alpha$$ decay and $$beta$$-delayed fission are two important decay modes of heavy exotic nuclei. Experimental $$alpha$$ decay and $$beta$$-delayed fission studies deliver significant nuclear-structure information in regions of the nuclear chart with limited accessibility. This information is important to improve the predictability of contemporary nuclear models used for e.g. nuclear astrophysics calculations. The basic principles and the current understanding of $$alpha$$ and $$beta$$-delayed fission decay are introduced. Examples of recent experiments and their impact on the understanding of heavy nuclei are presented.

論文

Detailed $$alpha$$-decay study of $$^{180}$$Tl

Andel, B.*; Andreyev, A. N.; Antalic, S.*; Barzakh, A.*; Bree, N.*; Cocolios, T. E.*; Comas, V. F.*; Diriken, J.*; Elseviers, J.*; Fedorov, D. V.*; et al.

Physical Review C, 96(5), p.054327_1 - 054327_11, 2017/12

https://doi.org/10.1103/PhysRevC.96.054327
 被引用回数：3 パーセンタイル：27.61(Physics, Nuclear)

A detailed $$alpha$$-decay spectroscopy study of $$^{180}$$Tl has been performed at ISOLDE (CERN). Z-selective ionization by the Resonance Ionization Laser Ion Source (RILIS) coupled to mass separation provided a high-purity beam of $$^{180}$$Tl. Fine-structure $$alpha$$ decays to excited levels in the daughter $$^{176}$$Au were identified and an $$alpha$$-decay scheme of $$^{180}$$Tl was constructed based on an analysis of $$alpha$$-$$gamma$$ and $$alpha$$-$$gamma$$ -$$gamma$$ coincidences. Multipolarities of several $$gamma$$-ray transitions deexciting levels in $$^{176}$$Au were determined. Based on the analysis of reduced $$alpha$$-decay widths, it was found that all $$alpha$$ decays are hindered, which signifies a change of configuration between the parent and all daughter states.

論文

Identification of the crossing point at $$N$$ = 21 between normal and intruder configurations

Lic$u{a}$, R.*; Rotaru, F.*; Borge, M. J. G.*; Gr$'e$vy, S.*; Negoita, F.*; Poves, A.*; Sorlin, O.*; Andreyev, A. N.; Borcea, R.*; Costache, C.*; et al.

Physical Review C, 95(2), p.021301_1 - 021301_6, 2017/02

https://doi.org/10.1103/PhysRevC.95.021301
 被引用回数：18 パーセンタイル：79.42(Physics, Nuclear)

The $$beta^{-}$$ decay of $$^{34}$$Mg was used to study the $$^{34}$$Al nucleus through $$gamma$$ spectroscopy at the Isotope Separator On-Line facility of CERN. Previous studies identified two $$beta$$-decaying states in $$^{34}$$Al having spin-parity assignments $$J^{pi}$$=4$$^{-}$$ dominated by the normal configuration $$pi$$(d5/2)$$^{-1}$$ $$bigoplus$$ $$nu$$(f7/2) and $$J^{pi}$$ = 1$$^{+}$$ by the intruder configuration $$pi$$(d5/2)$$^{-1}$$ $$bigoplus$$ $$nu$$(d3/2)$$^{-1}$$(f7/2)$$^{2}$$. Their unknown ordering and relative energy have been the subject of debate for the placement of $$^{34}$$Al inside or outside the $$N$$ = 20 "island of inversion". We report here that the 1$$^{+}$$ intruder lies only 46.6 keV above the 4$$^{-}$$ ground state. In addition, a new half-life of $$T_{1/2}$$=44.9(4)ms, that is twice as long as thepreviously measured 20(10) ms, has been determined for $$^{34}$$Mg. Large-scale shell-model calculations with the recently developed SDPF-U-MIX interaction are compared with the new data and used to interpret the mechanisms at play at the very border of the $$N$$ = 20 island of inversion.

論文

Changes in mean-squared charge radii and magnetic moments of $$^{179-184}$$Tl measured by in-source laser spectroscopy

Barzakh, A.*; Andreyev, A. N.; Cocolios, T. E.*; de Groote, R. P.*; Fedorov, D. V.*; Fedosseev, V. N.*; Ferrer, R.*; Fink, D. A.*; Ghys, L.*; Huyse, M.*; et al.

Physical Review C, 95(1), p.014324_1 - 014324_12, 2017/01

https://doi.org/10.1103/PhysRevC.95.014324
 被引用回数：26 パーセンタイル：86.67(Physics, Nuclear)

Hyperfine structure and isotope shifts have been measured for the ground and isomeric states in the neutron deficient isotopes $$^{179-184}$$Tl using the 276.9 nm transition. The experiment has been performed at the CERN Isotope Separator On-Line facility using the in-source resonance-ionization laser spectroscopy technique. Spins for the ground states in $$^{179,181,183}$$Tl have been determined as $$I$$ = 1/2. Magnetic moments and changes in the nuclear mean-square charge radii have been deduced. By applying the additivity relation for magnetic moments of the odd-odd Tl nuclei the leading configuration assignments were confirmed. A deviation of magnetic moments for isomeric states in $$^{182,184}$$Tl from the trend of the heavier Tl nuclei is observed. The charge radii of the ground states of the isotopes $$^{179-184}$$Tl follow the trend for isotonic (spherical) lead nuclei. The noticeable difference in charge radii for ground and isomeric states of $$^{183,184}$$Tl has been observed, suggesting a larger deformation for the intruder-based 9/2$$^{-}$$ and 10$$^{-}$$ states compared to the ground states. An unexpected growth of the isomer shift for $$^{183}$$Tl has been found.

論文

Beta-delayed proton emission from $$^{20}$$Mg

Lund, M. V.*; Andreyev, A. N.; Borge, M. J. G.*; Cederk$"a$ll, J.*; De Witte, H.*; Fraile, L. M.*; Fynbo, H. O. U.*; Greenlees, P. T.*; Harkness-Brennan, L. J.*; Howard, A. M.*; et al.

European Physical Journal A, 52(10), p.304_1 - 304_14, 2016/10

https://doi.org/10.1140/epja/i2016-16304-x
 被引用回数：17 パーセンタイル：75.78(Physics, Nuclear)

Beta-delayed proton emission from $$^{20}$$Mg has been measured at ISOLDE, CERN, with the ISOLDE Decay Station setup including both charged-particle and $$gamma$$-ray detection capabilities. A total of 27 delayed proton branches were measured including seven so far unobserved. An updated decay scheme, including three new resonances above the proton separation energy in $$^{20}$$Na and more precise resonance energies, is presented. Beta-decay feeding to two resonances above the Isobaric Analogue State in $$^{20}$$Na is observed. This may allow studies of the 4032.9(2.4) keV resonance in $$^{19}$$Ne through the beta decay of $$^{20}$$Mg, which is important for the astrophysically relevant reaction $$^{15}$$O($$alpha$$,$$gamma$$)$$^{19}$$Ne. Beta-delayed protons were used to obtain a more precise value for the half-life of $$^{20}$$Mg, 91.4(1.0) ms.

論文

$$beta$$-delayed fission and $$alpha$$ decay of $$^{196}$$At

Truesdale, V. L.*; Andreyev, A. N.; Ghys, L.*; Huyse, M.*; Van Duppen, P.*; Sels, S.*; Andel, B.*; Antalic, S.*; Barzakh, A.*; Capponi, L.*; et al.

Physical Review C, 94(3), p.034308_1 - 034308_11, 2016/09

https://doi.org/10.1103/PhysRevC.94.034308
 被引用回数：10 パーセンタイル：60.43(Physics, Nuclear)

A nuclear-decay spectroscopy study of the neutron-deficient isotope $$^{196}$$At is reported where an isotopically pure beam was produced using the selective Resonance Ionization Laser Ion Source and On-Line Isotope Mass Separator (CERN). The fine-structure $$alpha$$ decay of $$^{196}$$At allowed the low-energy excited states in the daughter nucleus $$^{192}$$Bi to be investigated. A $$beta$$-delayed fission study of $$^{196}$$At was also performed. A mixture of symmetric and asymmetric fission-fragment mass distributions of the daughter isotope $$^{196}$$Po (populated by $$beta$$ decay of $$^{196}$$At) was deduced based on the measured fission-fragment energies. A $$beta$$DF probability $$P_{rm beta DF}$$($$^{196}$$At) = 9(1)$$times$$10$$^{-5}$$ was determined.

論文

Short-lived isomers in $$^{192}$$Po and $$^{194}$$Po

Andel, B.*; Andreyev, A. N.; Antalic, S.*; He${ss}$berger, F. P.*; Ackermann, D.*; Hofmann, S.*; Huyse, M.*; Kalaninov$'a$, Z.*; Kindler, B.*; Kojouharov, I.*; et al.

Physical Review C, 93(6), p.064316_1 - 064316_12, 2016/06

https://doi.org/10.1103/PhysRevC.93.064316
 被引用回数：5 パーセンタイル：39.53(Physics, Nuclear)

Isomeric states in $$^{194}$$Po and $$^{192}$$Po were studied at the velocity filter SHIP. The isotopes were produced in the fusion-evaporation reactions $$^{141}$$Pr($$^{56}$$Fe, $$p2n$$)$$^{194}$$Po and $$^{144}$$Sm($$^{51}$$V, $$p2n$$)$$^{192}$$Po. Several new $$gamma$$-ray transitions were attributed to the isomers and $$gamma$$-$$gamma$$ coincidences for both isomers were studied for the first time. The 459-keV transition earlier, tentatively proposed as de-exciting the isomeric level in $$^{194}$$Po, was replaced by a new 248-keV transition, and the spin of this isomer was reassigned from (11$$^{-}$$) to (10$$^{-}$$). The de-excitation of the (11$$^{-}$$) isomeric level in $$^{192}$$Po by the 154-keV transition was confirmed and a parallel de-excitation by a 733-keV (E3) transition to (8$$^{+}$$) level of the ground-state band was suggested. Moreover, side feeding to the (4$$^{+}$$) level of the ground-state band was proposed. The paper also discusses strengths of transitions de-exciting 11$$^{-}$$ isomers in neighboring Po and Pb isotopes.

論文

Spectroscopy of $$^{46}$$Ar by the ($$t,p$$) two-neutron transfer reaction

Nowak, K.*; Wimmer, K.*; Hellgartner, S.*; M$"u$cher, D.*; Bildstein, V.*; Diriken, J.*; Elseviers, J.*; Gaffney, L. P.*; Gernh$"a$user, R.*; Iwanicki, J.*; et al.

Physical Review C, 93(4), p.044335_1 - 044335_10, 2016/04

https://doi.org/10.1103/PhysRevC.93.044335
 被引用回数：18 パーセンタイル：77.39(Physics, Nuclear)

The $$^{44}$$Ar($$t,p$$)$$^{46}$$Ar two-neutron transfer reaction at 2.16 MeV/u was studied at CERN using a $$^{44}$$Ar radioactive beam and a tritium loaded radioactive target. Angular distributions for three final states were measured and based on the shape of the differential cross section an excited state at 3695 keV was identified as the first excited 0$$+$$ state. The differential cross-sections for the 0$$^+$$-ground state, and first excited 2$$^+$$ and 0$$^+$$ states are compared to DWBA calculations including two-step reactions through the intermediate nucleus $$^{45}$$Ar. By comparison large scale shell model calculations using state-of-the-art effective interactions, with and without the tensor components of the interactions, it was observed that the cross-shell proton-neutron tensor interaction has measurable effects on the observables at low excitation energy in $$^{46}$$Ar.

論文

Fast-timing study of the $$l$$-forbidden 1/2$$^+$$ $$rightarrow$$ 3/2$$^+$$ $$M1$$ transition in $$^{129}$$Sn

Lic$u{a}$, R.*; Mach, H.*; Fraile, L. M.*; Gargano, A.*; Borge, M. J. G.*; M$u{a}$rginean, N.*; Sotty, C. O.*; Vedia, V.*; Andreyev, A. N.; Benzoni, G.*; et al.

Physical Review C, 93(4), p.044303_1 - 044303_7, 2016/04

https://doi.org/10.1103/PhysRevC.93.044303
 被引用回数：5 パーセンタイル：39.53(Physics, Nuclear)

The levels in $$^{129}$$Sn populated from the $$beta^-$$ decay of $$^{129}$$In isomers were investigated at the ISOLDE facility of CERN using the newly commissioned ISOLDE Decay Station. The lowest 1/2$$^+$$ state and the 3/2$$^+$$ ground state in $$^{129}$$Sn are expected to have configurations dominated by the neutron $$s_{1/2}$$ ($$l$$=0) and $$d_{3/2}$$ ($$l$$=2) single-particle states, respectively. Consequently, these states should be connected by a somewhat slow $$l$$-forbidden $$M1$$ transition. Using fast-timing spectroscopy we have measured the half-life of the 1/2$$^+$$ 315.3-keV state, $$T_{1/2}$$ = 19(10) ps, which corresponds to a moderately fast $$M1$$ transition. Shell-model calculations using the CD-Bonn effective interaction, with standard effective charges and $$g$$ factors, predict a 4-ns half-life for this level. We can reconcile the shell-model calculations to the measured $$T_{1/2}$$ value by the renormalization of the $$M1$$ effective operator for neutron holes.

41 件中 1件目～20件目を表示