2025-11-06 北海道大学
ニュートリノレス二重ベータ崩壊の親核またはその娘核の基底状態付近では、異なる形状が共存する場合があり、それが崩壊の半減期の決定に重要な役割を持つことが本研究で明らかとなった。図の|ΨX>と|ΨY>はそれぞれ親核、娘核の基底状態を表し、親核はレモン型形状を呈し、娘核では球形とミカン型形状の共存を模式的に示す。
＜関連情報＞
- https://www.hokudai.ac.jp/news/2025/11/post-2117.html
- https://www.hokudai.ac.jp/news/pdf/251106_pr.pdf
- https://www.sciencedirect.com/science/article/pii/S0370269325007531
ニュートリノレス二重ベータ崩壊核行列要素への配位混合の効果 Configuration mixing effects on neutrinoless ββ-decay nuclear matrix elements
Kosuke Nomura
Physics Letters B Available online: 30 October 2025
DOI:https://doi.org/10.1016/j.physletb.2025.139995
Abstract
Mixing and coexistence of intrinsic nuclear shapes play an important role to determine the low-energy structure of heavy nuclei, and are expected to affect nuclear matrix elements (NMEs) of neutrinoless double beta (0νββ) decay. This problem is addressed in the interacting boson model with configuration mixing that is formulated by using the nuclear energy density functional theory. It is shown that significant amounts of mixing of normal and deformed intruder configurations are present in the ground and excited 0+ states in the even-even nuclei that are parent or daughter nuclei of the 0νββ decay. An illustrative application to the 0νββ decays of 76Ge, 96Zr, 100Mo, 116Cd, and 150Nd shows that the inclusion of the configuration mixing reduces the NMEs for most of the 0+1→0+10νββ decays.
