论文标题
（n，$γ$）不稳定同位素的反应速率不确定性对从BA到W的元素的I过程的核合成的影响
The impact of (n,$γ$) reaction rate uncertainties of unstable isotopes on the i-process nucleosynthesis of the elements from Ba to W
论文作者
论文摘要
CEMP-R/S星中N捕获元素的丰度与中间n密度的核合成的预测，为$ n_ \ mathrm {n} \ sim 10^{13} $ - $ 10^{13} $ - $ 10^{15} {15} \ MATHRM {cm}^cm}^{cm}^{-3} $ jaust jaust papid whitely-accrfs rawd whethly-accrfs rawd dw dw dw dw dw dw dw dw dw dw dw dw dw。我们已经对这种I过程的核合成进行了蒙特卡洛模拟，以确定（n，$γ$）的反应速率不确定性的影响，从$^{131} $ i至$^{$^{189} $ hf对BA的18个元素的预测范围，对ba的预测丰富的量。美元在[fe/h] = -2.6的RAWD模型中插入H的He壳对流。对于每个选定的元素，我们已经确定了多达两个（n，$γ$）的反应，其速率变化受到Hauser-Feshbach计算的限制和预测的丰度，具有Pearson Product Product-Moment-Moment相关系数$ | r_ \ r_ \ r_ \ nathrm {p} | > 0.15 $。我们发现，如果$^{137} $ cs（n，$γ）^{138} $ cs降低了$^{137} $ cs（n，$γ）$ cs（n，$γ）$ cs（$^{137} $ cs的比率，并且降低了$^{141 $ ba $^{141} $ ba（n，ba ba（n），则CEMP-I星CS31062-050中预测和观察到的BA和PR之间的差异显着降低。 $^{141} $ la（n，$γ）^{142} $ la增加。相同不稳定同位素的温度依赖性$β$ - 定率的不确定性对预测的丰度具有可忽略的影响。单区蒙特卡洛模拟可以使用，而不是计算时间耗时的多区域蒙特卡洛模拟，如果他们使用$ n_ \ mathrm {n} $的可比值（删节），则可以使用反应速率不确定性研究。
The abundances of n-capture elements in the CEMP-r/s stars agree with predictions of intermediate n-density nucleosynthesis, at $N_\mathrm{n}\sim 10^{13}$-$10^{15} \mathrm{cm}^{-3}$, in rapidly-accreting white dwarfs (RAWDs). We have performed Monte-Carlo simulations of this i-process nucleosynthesis to determine the impact of (n,$γ$) reaction rate uncertainties of 164 unstable isotopes, from $^{131}$I to $^{189}$Hf, on the predicted abundances of 18 elements from Ba to W. The impact study is based on two representative one-zone models with constant values of $N_\mathrm{n} = 3.16\times 10^{14}\ \mathrm{cm}^{-3}$ and $N_\mathrm{n} = 3.16\times 10^{13}\ \mathrm{cm}^{-3}$ and on a multi-zone model based on a realistic stellar evolution simulation of He-shell convection entraining H in a RAWD model with [Fe/H]=-2.6. For each of the selected elements, we have identified up to two (n,$γ$) reactions having the strongest correlations between their rate variations constrained by Hauser-Feshbach computations and the predicted abundances, with the Pearson product-moment correlation coefficients $|r_\mathrm{P}| > 0.15$. We find that the discrepancies between the predicted and observed abundances of Ba and Pr in the CEMP-i star CS31062-050 are significantly diminished if the rate of $^{137}$Cs(n,$γ)^{138}$Cs is reduced and the rates of $^{141}$Ba(n,$γ)^{142}$Ba or $^{141}$La(n,$γ)^{142}$La increased. The uncertainties of temperature-dependent $β$-decay rates of the same unstable isotopes have a negligible effect on the predicted abundances. One-zone Monte-Carlo simulations can be used instead of computationally time-consuming multi-zone Monte-Carlo simulations in reaction rate uncertainty studies if they use comparable values of $N_\mathrm{n}$ (abridged).
