论文标题
低能充电$ν_e$在$^{40} $ ar上散射的核去激发
Nuclear de-excitations in low-energy charged-current $ν_e$ scattering on $^{40}$Ar
论文作者
论文摘要
背景：大型基于氩的中微子探测器，例如计划进行深地下中微子实验的中微子探测器，具有对由核心 - 循环超新星产生的低能（几至MeV）电子中微子的独特敏感性。尽管它们对中微子能源重建的重要性，但在$^{40} $ ar上充电$ν_e$吸收后，核去激发的核能解脱从未在Supernova Energies上进行详细研究。 目的：我开发了一个核去凝模型的模型，该模型是在$^{40} \ mathrm {ar}（ν_e，e^{ - }）^{40} \ Mathrm {k}^*$反应的情况下发生的。该模型应用于排他性横截面的计算。 方法：在允许的近似值下得出了包含差分横截面的简单表达式。使用测量的$γ$ - 雷衰减方案和Hauser-Feshbach统计模型的组合来描述核能解脱。所有计算都是使用名为Marley的新型蒙特卡洛事件发生器（Argon反应模型低能量产量）进行的。 结果：介绍了各种总和横截面。发现两种启用模式，一种仅涉及$γ$ -rays，另一种包括单个中子发射，在少数几十ev的能量下占主导地位。 结论：核能解脱对超新星$ν_e$检测的可实现的能量分辨率有很大的影响。标记涉及中子排放的事件虽然很困难，但可以大大改善能量重建。考虑到包容性横截面的合适计算，Marley核能解脱模型可以很容易地应用于其他散射过程。
Background: Large argon-based neutrino detectors, such as those planned for the Deep Underground Neutrino Experiment, have the potential to provide unique sensitivity to low-energy (few to tens of MeV) electron neutrinos produced by core-collapse supernovae. Despite their importance for neutrino energy reconstruction, nuclear de-excitations following charged-current $ν_e$ absorption on $^{40}$Ar have never been studied in detail at supernova energies. Purpose: I develop a model of nuclear de-excitations that occur following the $^{40}\mathrm{Ar}(ν_e,e^{-})^{40}\mathrm{K}^*$ reaction. This model is applied to the calculation of exclusive cross sections. Methods: A simple expression for the inclusive differential cross section is derived under the allowed approximation. Nuclear de-excitations are described using a combination of measured $γ$-ray decay schemes and the Hauser-Feshbach statistical model. All calculations are carried out using a novel Monte Carlo event generator called MARLEY (Model of Argon Reaction Low Energy Yields). Results: Various total and differential cross sections are presented. Two de-excitation modes, one involving only $γ$-rays and the other including single neutron emission, are found to be dominant at few tens-of-MeV energies. Conclusions: Nuclear de-excitations have a strong impact on the achievable energy resolution for supernova $ν_e$ detection in liquid argon. Tagging events involving neutron emission, though difficult, could substantially improve energy reconstruction. Given a suitable calculation of the inclusive cross section, the MARLEY nuclear de-excitation model may readily be applied to other scattering processes.
