Multi-quasiparticle sub-nanosecond isomers in 178W
Multi-quasiparticle sub-nanosecond isomers in 178W
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DOI：
10.1016/j.physletb.2019.135140
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发表时间：
2020-02
影响因子：
4.4
通讯作者：
M. Rudigier;P. Walker;R. Canavan;Z. Podolyák;P. Regan;P. Söderström;M. Lebois;J. Wilson;N. Jovančević;A. Blazhev;J. Benito;S. Bottoni;M. Brunet;N. Cieplicka-Oryńczak;S. Courtin;D. Doherty;L. Fraile;K. Hadyńska-Klęk;M. Heine;Ł. Iskra;J. Jolie;V. Karayonchev;A. Kennington;P. Koseoglou;G. Lotay;G. Lorusso;M. Nakhostin;C. Nita;S. Oberstedt;L. Qi;J. Régis;V. Sánchez-Tembleque;R. Shearman;W. Witt;V. Vedia;K. Zell
中科院分区：
文献类型：
--
作者：
M. Rudigier;P. Walker;R. Canavan;Z. Podolyák;P. Regan;P. Söderström;M. Lebois;J. Wilson;N. Jovančević;A. Blazhev;J. Benito;S. Bottoni;M. Brunet;N. Cieplicka-Oryńczak;S. Courtin;D. Doherty;L. Fraile;K. Hadyńska-Klęk;M. Heine;Ł. Iskra;J. Jolie;V. Karayonchev;A. Kennington;P. Koseoglou;G. Lotay;G. Lorusso;M. Nakhostin;C. Nita;S. Oberstedt;L. Qi;J. Régis;V. Sánchez-Tembleque;R. Shearman;W. Witt;V. Vedia;K. Zell
本文报道了首次测量偶偶核178W中K-π=11−和12+四准粒子态的半衰期。用质心移动法测量了法国奥赛装置的LaBr3(Ce)闪烁探测器测量的亚纳秒半衰期。这些状态的半衰期只有通过几种实验技术的组合才能在实验上获得--闪烁体快速计时，脉冲光束的同质异能谱，以及由NuBall阵列提供的逐个事件的量热信息。测得Iπ=11−和12+态的半衰期分别为476(44)ps和275(65)ps。衰变包括弱受阻的E1和E2分支，绕过两准粒子态，直接到达基态带。这是第一次对e1跃迁进行这样的观测。对小势垒的解释取决于基态带和t带之间的混合。
We report on the first measurement of the half-lives of K π= 11− and 12+ four-quasiparticle states in the even-even nucleus 178 W. The sub-nanosecond half-lives were measured by applying the centroid shift method to data taken with LaBr 3 (Ce) scintillator detectors of the NuBall array at the ALTO facility in Orsay, France. The half-lives of these states only became experimentally accessible by the combination of several experimental techniques-scintillator fast timing, isomer spectroscopy with a pulsed beam, and the event-by-event calorimetry information provided by the NuBall array. The measured half-lives are 476 (44) ps and 275 (65) ps for the I π= 11− and 12+ states, respectively. The decay transitions include weakly hindered E1 and E2 branches directly to the ground-state band, bypassing the two-quasiparticle states. This is the first such observation for an E1 transition. The interpretation of the small hindrance hinges on mixing between the ground-state band and the t-band.