The production of heavy-mass elements due to the rapid neutron-capture mechanism (r-process) is associated with astrophysical scenarios, such as supernovae and neutron-star mergers. In the r-process the capture of neutrons is followed by β-decays until nuclear stability is reached. A key element in the chain of nuclear weak-decays leading to the production of isotopes may be the change of the parameters controlling the neutrino sector, due to the mixing of active and sterile species. In this work, we have addressed this question and calculated β-decay rates for the nuclei involved in the r-process chains as a function of the neutrino mixing parameters. These rates are then used in the calculation of the abundance of the heavy elements produced in core-collapse supernova and in neutron-star mergers, starting from different initial mass-fraction distributions. The analysis shows that the core-collapse supernova environment contributes with approximately 30% of the total heavy nuclei abundance while the neutron-star merger contributes with about 70% of it. Using available experimental data we have performed a statistical analysis to set limits on the active-sterile neutrino mixing angle and found a best-fit value sin22𝜃 14 = 0.22, a value comparable with those found in other studies reported in the literature.

中文翻译：

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使用重核丰度对活性-无菌中微子混合参数的限制

由于快速中子捕获机制产生的大质量元素（r-过程）与天体物理场景相关，例如超新星和中子星合并。在里面r- 处理中子的捕获，然后是β-衰变直到达到核稳定性。导致同位素产生的核弱衰变链中的一个关键因素可能是由于活性物质和无菌物质的混合，控制中微子部分的参数发生了变化。在这项工作中，我们已经解决了这个问题并计算了β- 参与核的衰变率r-过程链作为中微子混合参数的函数。然后将这些速率用于计算核心坍缩超新星和中子星合并中产生的重元素的丰度，从不同的初始质量分数分布开始。分析表明，核心坍缩超新星环境贡献了大约30%总重核丰度，而中子星合并贡献了大约70%其中。使用可用的实验数据，我们进行了统计分析，以设置活性-无菌中微子混合角的限制，并找到了一个最佳拟合值罪22𝜃 14 = 0.22，该值与文献报道的其他研究中发现的值相当。