Muon capture on the deuteron and 3He
Muon capture on the deuteron and 3He
复制标题
氘核和 3He 上的 μ 子捕获
DOI：
10.1051/epjconf/20148106004
复制
发表时间：
2014
影响因子：
4.4
通讯作者：
A. Elmeshneb
中科院分区：
文献类型：
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作者：
A. Elmeshneb
我们计划研究介子交换电流在描述μ−+d→νμ+n+n和μ−+3He→νμ+3H反应中的作用。它们都被视为相应的介子原子的衰变，而介子最初位于最低的K壳层。这些原子中的µ子结合能可以被安全地忽略，在初始状态下，我们主要处理重离子(或~3He)和静止的µ子。这两种反应之所以有趣，有几个原因。首先，它们为核波函数提供了一个试验场，对于任何核子-核子(NN)和三核子(3N)力，都可以非常精确地为这样的轻子系统构造。在这些反应中，少核子弱电流算符是一个重要的动力学成分。在目前的算符中，除了相对广为人知的单核子贡献外，双核子部分(由各种介子交换产生)发挥着重要作用。他们的细节并不为人所知，应该考虑几种模式。我们给出了处理这些反应的公式和两核子算符分波分解的一种简单方法。相应的弱电流算符的关键核矩阵元素将在动量空间中使用分波分解来计算。介子交换的影响将在发射的中微子的能谱(在质子情况下)和两个反应的总衰减率中进行研究。我们将使用NN和3N力的各种模型，例如波恩B势或手征NNLO势。我们关于单核子电流的结果看起来已经很有希望了，我们希望当我们的框架中包含主要的双核子电流算符时，对实验数据的描述能有所改进。
We plan to investigate the role of meson exchange currents in the description of the μ − + d → νμ + n + n and μ − + 3 He → νμ + 3 H reactions. They both are treated as the decay of the corresponding muonic atoms, with the muon initially on the lowest K shell. The muon binding energy in these atoms can be safely neglected and in the initial state we deal essentially with the deuteron (or 3 He) and muon at rest. These two reactions are interesting for several reasons. First of all, they offer a testing ground for the nuclear wave functions, which for any nucleon-nucleon (NN) and three-nucleon (3N) forces can be constructed for such light systems with great accuracy. In these reactions few-nucleon weak current operators are an important dynamical ingredient. In the current operators apart from the relatively well known single nucleon contributions, two-nucleon parts (generated by various meson exchanges) play an important role. Their details are not well known and several models should be considered. We present our formalism for dealing with these reactions and a simple method for partial wave decomposition of the two-nucleon operators. The crucial nuclear matrix elements of the corresponding weak current operators will be calculated in the momentum space and using partial wave decomposition. The effect of meson exchanges will be investigated in the energy spectrum of the emitted neutrinos (in the deuteron case) and in the total decay rates for the two reactions. We will employ various models of NN and 3N forces, such as the Bonn B or chiral NNLO potentials. Our results with the single nucleon currents look already very promising and we hope for the improvement in the description of the experimental data, when dominant two-nucleon current operators are included in our framework.