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arXiv 2212.03271nucl-thnucl-ex
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含时Dirac方程在单质子放射性辐射中的应用

Time-dependent Dirac equation applied to one-proton radioactive emission

Tomohiro Oishi

摘要:

相对论能量密度泛函(REDF)理论已经发展并用于原子核的自洽平均场计算。质子发射放射性能为提高REDF的预测能力,特别是在质子滴注线上的预测能力提供了一个合适的参考。人们需要考虑量子隧道效应,它在核子发射放射性过程中发挥着至关重要的作用。然而,相对论量子隧穿的研究相对于非相对论情况较少。本文基于相对论狄拉克理论,对单质子($1p$)的放射性进行了理论计算。为此,我开发了含时(TD)的狄拉克旋量计算来模拟$1p$发射。利用相对论性Hartree-Bogoliubov(RHB)方法和DD-PCX参数,确定了含时Dirac旋量的单质子势.本文用TD-Dirac方法计算了$^{37}$ Sc和$^{39}$ Sc核的$1p$辐射,这些核可以很好地近似为价质子和质子密壳核.证明了$1p$发射能量和衰减宽度对质量数的敏感性。由于体系的大小对势和能级的核部分有显著的影响,而库仑势垒对相同的原子序数是常见的。计算的$1p$能量和衰减寿命与实验极限基本一致。为了利用$1p$发射数据改进REDF,本文的TD-Dirac计算有望广泛应用于丰质子核素。

英文摘要:

Relativistic energy-density functional (REDF) theory has been developed and utilized for self-consistent meanfield calculations of atomic nuclei. The proton-emitting radioactivity can provide a suitable reference to improve the predicting ability of REDF especially on the proton-drip line. One needs to consider the quantum tunneling effect, which plays an essential role in nucleon-emitting radioactive processes. However, the relativistic quantum tunneling has been less investigated compared with the non-relativistic case. This work is devoted to a theoretical evaluation of one-proton ($1p$) radioactivity based on the relativistic Dirac formalism. For this purpose, I develop the time-dependent (TD) Dirac-spinor calculation to simulate the $1p$ emission. By utilizing the relativistic Hartree-Bogoliubov (RHB) calculation with the DD-PCX parameters, single-proton potentials for the time-dependent Dirac spinor are determined. The TD-Dirac calculation is applied to the $1p$ emissions from the $^{37}$Sc and $^{39}$Sc nuclei, which can be well approximated as the valence proton and the proton-close-shell cores. The sensitivity of $1p$-emission energy and decaying width to the mass number is demonstrated. Remarkable sensitivity exists due to the size of system, which affects the nuclear part of potentials and energy levels, whereas the Coulomb barrier is common with the same atomic number. The calculated $1p$ energy and decaying lifetime are roughly consistent to the experimental limitation. The present TD-Dirac calculation is expected as applicable widely to proton-rich nuclides in order to improve the REDF by utilizing the $1p$-emission data.

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。

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