多核子移行反応における殻効果の二重の役割を解明（Study Reveals the Dual Role of Shell Effects in Multinucleon Transfer Reactions）

2026-07-09 中国科学院（CAS）

Schematic diagram of multinucleon transfer reaction (Image by DAI Fanchao)

＜関連情報＞

• https://english.cas.cn/newsroom/research-news/202607/t20260710_1177086.shtml
• https://www.sciencedirect.com/science/article/pii/S0370269326004661

中性子過剰核の生成における殻効果の役割N=126 多核子移行反応による領域 Role of shell effects on producing neutron-rich nuclei in the N=126 region via multinucleon transfer reactions

F.C. Dai, P.W. Wen, C.J. Lin, J.J. Liu, X.X. Xu, K.L. Wang, Y.D. Chen, H.L. Yang
Physics Letters  Available online: 4 June 2026
DOI:https://doi.org/10.1016/j.physletb.2026.140614

Abstract

Neutron-rich nuclei near the N=126 shell closure are vital for r-process nucleosynthesis but remain challenging to produce. Multinucleon transfer reactions offer a promising route. We investigate the role of shell effects in such processes by extending the CLIM-H model with a deformation-dependent mass formula and a scaling factor a that linearly adjusts the shell-correction strength. Calculations for ¹³⁶Xe on ²⁰⁸Pb, ²⁰⁴Hg, and ²⁰⁸Hg targets reveal a dual role: shell effects enhance few-nucleon transfers near the entrance channel but strongly suppress fragments requiring the transfer of many nucleons, most severely for the doubly magic ²⁰⁸Pb. This suppression stems from the cumulative transfer probabilities and is aggravated by lower survival after deexcitation. Thus, optimal production of exotic N=126 nuclei requires avoiding strongly shell-closed collision partners at N=126 , as exemplified by doubly magic ²⁰⁸Pb. We propose ²³⁸U + ²⁰⁴Hg at E_c.m. ≃ 1.45 V_B as a superior system, predicting significantly enhanced yields.