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arXiv 2402.11535nucl-thnucl-ex
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核能级密度数据的贝叶斯不确定性量化及其对天体物理相关$(p,\gamma)$反应的影响

Bayesian uncertainty quantification on nuclear level density data and their impact on $(p,γ)$ reactions of astrophysical interest

A. Chalil, C. Ducoin, O. Stézowski, N. Millard-Pinard, J. Dudouet, Y. Demane, M. Chamseddine

AI总结:

本研究利用贝叶斯优化量化两种核能级密度模型参数的95%高密度区间,并将不确定性传播至天体物理相关能量范围内的$(p,\gamma)$反应截面,发现其显著缩小了TALYS默认模型的截面预测范围,强调了获取相关能级密度数据的必要性。

摘要:

$p$过程核合成负责合成从$^{35}$Se到$^{196}$Hg的35种中子 deficient 核素。影响该过程建模的一个重要输入是反应网络中所涉核在相关激发能处的核能级密度。OSLO方法已被广泛用于测量几个MeV激发能处的能级密度。本研究使用贝叶斯优化,估算了在OSLO数据上优化的两种能级密度模型参数的95%高密度区间。随后将这些不确定性传播至天体物理相关能量范围内生成复合核$^{105,106}$Pd和$^{105,106}$Cd的$(p,\gamma)$反应截面中。对该同位素图区域施加约束,对于涉及邻近$p$核素$^{102}$Pd和$^{106}$Cd的网络计算非常重要。我们讨论了由于能级密度数据不确定性导致的截面范围缩小情况,并将其与TALYS中六种默认能级密度模型的范围进行了比较,同时强调了在天体物理相关能量范围内获取能级密度数据的必要性。

英文摘要:

The $p$ process nucleosynthesis is responsible for the synthesis of 35 neutron-deficient nuclei from $^{35}$Se to $^{196}$Hg. An important input that can affect the modeling of this process is the nuclear level density at the relevant excitation energies of the nuclei involved in the reaction network. The OSLO method has been extensively used for the measurement of level densities in excitation energies of several MeV. In this work, Bayesian optimization has been used in order to estimate the 95% high density intervals for the parameters of two level density models optimized on the OSLO data. These uncertainties are then propagated on the cross sections of $(p,γ)$ reactions leading to the compound nuclei $^{105,106}$Pd and $^{105,106}$Cd inside the astrophysically relevant energy range. Imposing constraints in this region of the isotopic chart is important for network calculations involving the nearby $p$ nuclei $^{102}$Pd and $^{106}$Cd. We discuss the reduction of the range of cross sections due to the uncertainties arising from the level density data compared to the range of the six default level density models available in TALYS and we highlight the need for level density data inside the astrophysically relevant energy ranges.

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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