検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年
検索結果: 4 件中 1件目~4件目を表示
  • 1

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

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

 被引用回数:1 パーセンタイル:19.67(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

Competition between allowed and first-forbidden $$beta$$ decay; The Case of $$^{208}$$Hg $$rightarrow$$ $$^{208}$$Tl

Carroll, R. J.*; Podoly$'a$k, Zs.*; Berry, T.*; Grawe, H.*; Alexander, T.*; Andreyev, A. N.; Ansari, S.*; Borge, M. J. G.*; Brunet, M.*; Creswell, J. R.*; et al.

Physical Review Letters, 125(19), p.192501_1 - 192501_6, 2020/11

 被引用回数:6 パーセンタイル:62.96(Physics, Multidisciplinary)

The $$beta$$ decay of $$^{208}$$Hg into the one-proton hole, one neutron-particle $$^{208}_{81}$$Tl$$_{127}$$ nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the $$N > 126$$, $$Z < 82$$ quadrant of neutron-rich nuclei. While both negative and positive parity states with spin 0 and 1 are expected within the $$Q_{beta}$$ window, only three negative parity states are populated directly in the $$beta$$ decay. The data provide a unique test of the competition between allowed Gamow-Teller and Fermi, and first-forbidden $$beta$$ decays, essential for the understanding of the nucleosynthesis of heavy nuclei in the rapid neutron capture process. Furthermore, the observation of the parity changing $$0^{+} rightarrow 0^{-} beta$$ decay where the daughter state is core excited is unique, and can provide information on mesonic corrections of effective operators.

論文

Transition strengths in the neutron-rich $$^{73,74,75}$$Ni isotopes

Gottardo, A.*; De Angelis, G.*; Doornenbal, P.*; Coraggio, L.*; Gargano, A.*; Itaco, N.*; Orlandi, R.; 他52名*

Physical Review C, 102(1), p.014323_1 - 014323_8, 2020/07

 被引用回数:7 パーセンタイル:70.75(Physics, Nuclear)

Reduced transition probabilities have been measured for the neutron-rich $$^{73,74,75}$$Ni nuclei with relativistic Coulomb excitation performed at the RIKEN Nishina Center. Excitation energies compare well with the result of large-scale shell-model calculations, while $$B(E2)$$ values are larger than predicted. This could indicate an increasing contribution of proton excitations across the $$Z=28$$ shell closure when approaching $$^{78}$$Ni.

論文

$$^7$$Be(n,p)$$^7$$Li reaction and the cosmological lithium problem; Measurement of the cross section in a wide energy range at n_TOF at CERN

Damone, L.*; Barbagallo, M.*; Mastromarco, M.*; Cosentino, L.*; 原田 秀郎; 木村 敦; n_TOF Collaboration*; 他152名*

Physical Review Letters, 121(4), p.042701_1 - 042701_7, 2018/07

 被引用回数:47 パーセンタイル:92.13(Physics, Multidisciplinary)

We report on the measurement of the $$^7$$Be(n,p)$$^7$$Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a $$^7$$Be ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal $$^7$$Li(p,n)$$^7$$Be reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near threshold neutron production in the p+$$^7$$Li reaction is also discussed.

4 件中 1件目~4件目を表示
  • 1