Center for Nuclear Study, The University of Tokyo, Bunkyo-ku, Hongo, Tokyo 113-0033, Japan.
Phys Rev Lett. 2018 Apr 6;120(14):142502. doi: 10.1103/PhysRevLett.120.142502.
We study the double Gamow-Teller (DGT) strength distribution of ^{48}Ca with state-of-the-art large-scale nuclear shell model calculations. Our analysis shows that the centroid energy of the DGT giant resonance depends mostly on the isovector pairing interaction, while the resonance width is more sensitive to isoscalar pairing. Pairing correlations are also key in neutrinoless ββ (0νββ) decay. We find a simple relation between the centroid energy of the ^{48}Ca DGT giant resonance and the 0νββ decay nuclear matrix element. More generally, we observe a very good linear correlation between the DGT transition to the ground state of the final nucleus and the 0νββ decay matrix element. The correlation, which originates on the dominant short-range character of both transitions, extends to heavier systems including several ββ emitters and also holds in energy-density functional results. Our findings suggest that DGT experiments can be a very valuable tool to obtain information on the value of 0νββ decay nuclear matrix elements.
我们利用最先进的大规模核壳模型计算研究了^{48}Ca 的双 Gamow-Teller（DGT）强度分布。我们的分析表明，DGT 巨共振的质心能量主要取决于同位旋对相互作用，而共振宽度对同位旋更敏感。配对相关在中微子无ββ（0νββ）衰变中也是关键的。我们发现^{48}Ca DGT 巨共振的质心能量与 0νββ 衰变核矩阵元之间存在简单关系。更一般地，我们观察到 DGT 跃迁到最终核基态与 0νββ 衰变矩阵元之间存在非常好的线性相关性。这种相关性源于两种跃迁的主导短程特征，扩展到包括几个ββ发射体的较重系统，并在能量密度泛函结果中成立。我们的发现表明，DGT 实验可以成为获取有关 0νββ 衰变核矩阵元值信息的非常有价值的工具。
