论文标题
$^{48} $ ca和$^{78} $ ni的gamow-teller强度与电荷交换减去第二个随机相近似
Gamow-Teller strength in $^{48}$Ca and $^{78}$Ni with the charge-exchange subtracted second random-phase approximation
论文作者
论文摘要
我们开发了具有Skyrme能量密度函数的电荷交换过程的完全自洽的第二个随机相近似。作为第一个应用，我们研究了可以在实验中使用的最轻的双 - $β$发射器，在双粘性核$^{48} $ ca中研究gamow-teller激发，在$^{78} $ ni中，是已知的单-β-蛋白率。低于20或30 MEV的游戏性强度的量比其他能量密度功能的计算要小得多，并且与$^{48} $ CA中的实验更好，beta-decay速率在$^{78} $ ni中也是如此。这些重要结果，没有\ textit {ad hoc}淬火因子，是由于存在两个粒子的存在 - 两孔配置。它们的密度逐渐随激发能量而增加，导致光谱中长长的高能量尾巴，这一事实可能对在同一框架中对中性中心元的核基质元素的计算对中性中心元的double-β$衰减有影响。
We develop a fully self-consistent subtracted second random-phase approximation for charge-exchange processes with Skyrme energy-density functionals. As a first application, we study Gamow-Teller excitations in the doubly-magic nucleus $^{48}$Ca, the lightest double-$β$ emitter that could be used in an experiment, and in $^{78}$Ni, the single-beta-decay rate of which is known. The amount of Gamow-Teller strength below 20 or 30 MeV is considerably smaller than in other energy-density-functional calculations and agrees better with experiment in $^{48}$Ca, as does the beta-decay rate in $^{78}$Ni. These important results, obtained without \textit{ad hoc} quenching factors, are due to the presence of two-particle -- two-hole configurations. Their density progressively increases with excitation energy, leading to a long high-energy tail in the spectrum, a fact that may have implications for the computation of nuclear matrix elements for neutrinoless double-$β$ decay in the same framework.
