arXiv 2302.002582023-02-02nucl-th

双质子放射性的扩展R矩阵描述

Extended R-matrix description of two-proton radioactivity

Zhaozhan Zhang, Cenxi Yuan, Chong Qi, Boshuai Cai, Xinxing Xu

备注：: version accepted for publication in Physics Letters B
DOI：: 10.1016/j.physletb.2023.137740

摘要：

双质子（$2p$）放射性提供了关于三体衰变机制和剩余核相互作用的基础知识。在本文中，我们在扩展的R-矩阵框架下提出了不同衰变机制的衰变宽度公式，包括序列$2p$衰变、双质子衰变、三体衰变和序列双双质子衰变.结合双核子转移振幅和Wigner单粒子约化宽度的信息，双质子和三体公式可以很好地再现实验$2p$放射性半衰期。对于$^{67}$ Kr的情况，直接$2p$衰变的理论预测给出的半衰期比RIKEN最近的测量值大得多。直接和顺序的$2p$发射的组合进行了分析，考虑一个小的负一质子分离能和可能的增强贡献的$p$波分量。本方法预测，$^{71}$ Sr和$^{74}$ Zr可能是未来研究$2p$放射性的最有前途的候选者。我们的模型给出了最近发现的四质子共振核素$^{18}$ Mg的$4p$辐射的衰变宽度上限为55（4）keV，这与观测到的115（100）keV的宽度一致。

英文摘要：

Two-proton ($2p$) radioactivity provides fundamental knowledge on the three-body decay mechanism and the residual nuclear interaction. In this work, we propose decay width formulae in the extended R-matrix framework for different decay mechanisms, including sequential $2p$ decay, diproton decay, tri-body decay, and sequential two-diproton decay. The diproton and tri-body formulae, combined with information on the two-nucleon transfer amplitude and Wigner single-particle reduced width, can reproduce well experimental $2p$ radioactivity half-lives. For the case of $^{67}$Kr, theoretical predictions for direct $2p$ decay give much larger half-lives than the recent measurement from RIKEN. A combination of direct and sequential $2p$ emission is analyzed by considering a small negative one-proton separation energy and a possible enhanced contribution from the $p$-wave component. The present method predicts that $^{71}$Sr and $^{74}$Zr may be the most promising candidates for future study on $2p$ radioactivity. Our model gives an upper limit of 55(4) keV for the decay width of $4p$ emission in recently found four-proton resonant nuclide, $^{18}$Mg, which agrees with the observed width of 115(100) keV.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文