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arXiv 1607.04426nucl-th
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β衰变半衰期的新相空间计算

New phase space calculations for beta-decay half-lives

Sabin Stoica, Mihail Mirea, Ovidiu Nitescu, Jameel-Un Nabi, Mavra Ishfaq

摘要:

我们重新计算的相空间因子(PSF)的正电子衰变和电子捕获(EC)过程中涉及的大量的实验感兴趣的核。为了得到计算中所需的电子/正电子波函数,我们开发了一个精确求解Dirac方程的程序,该程序的核势是由真实的质子密度分布导出的。有限核尺寸(FNS)和屏蔽效应包括通过配方,不同于那些在以前的计算中使用。比较我们的结果与以前的计算采用近似的方法,但计算相同的Q值,我们发现一个密切的协议,为正电子衰变,而EC过程有相关的差异。对于EC过程,我们还发现屏蔽效应对计算的PSF值有显著的影响,特别是对于轻核。此外,我们重新计算了相同的PSF值,但使用文献中报道的最新Q值。在几种情况下,这些新的Q值显着不同,从旧的,这导致在PSF值与以前的结果相比,有很大的差异。这些新的PSF值的建议,可以有助于更可靠的计算β衰变率,这是在远离稳定线的核研究的关键量,以及更好地了解恒星演化。

英文摘要:

We revisit the computation of the phase space factors (PSF) involved in the positron decay and electron capture (EC) processes for a large number of nuclei of experimental interest. To obtain the electron/positron wave functions needed in computation, we develop a code for solving accurately the Dirac equation with a nuclear potential derived from a realistic proton density distribution in the nucleus. The finite nuclear size (FNS) and screening effects are included through recipes which differ from those used in previous calculations. Comparing our results with former calculations employing approximate methods but computed with the same Q-values, we find a close agreement for positron decays, while for the EC process there are relevant differences. For the EC process we also find that the screening effect has a notable influence on the computed PSF values specially for light nuclei. Further, we re-computed the same PSF values but using the most recent Q-values reported in literature. In several cases these new Q-values differ significantly from the older ones, which results in large differences in the PSF values as compared with previous results. These new PSF values proposed here, can contribute to a more reliable calculation of the beta decay rates, which are key quantities in the study of nuclei far from the stability line, as well as to better understanding of the stellar evolution.

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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