Ab initio Prediction of the 163Ho Electron Capture Spectrum

163Ho 电子捕获谱的从头预测

• 批准号: 400329440
• 负责人: Professor Dr. Maurits Haverkort
• 金额: --
• 依托单位: Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/400329440?language=en
• 关键词: Ab; initio; Prediction; 163Ho; Electron

Within this workgroup, we will ab initio predict the calorimetric electron capture spectra of 163Ho. From the particle physics point of view, the weak interaction of an electron with a proton leading to the creation of a neutron and an electron neutrino is theoretically straightforward. In a neutral atom, when this same interaction occurs, more complex processes will accompany the electron capture by the nucleus. Electrons in an atom are not independent identities and due to strong Coulomb forces, all electrons react once one electron is captured. The calorimetrically measured spectrum of Ho is thus not given by just 7 Lorentzian shaped peaks originating from capture events from the 3s to 6s and 3p1/2 to 5p1/2 shell respectively, but several additional shake-up and shake-off structures with an involved multiplet structure emerge. The theoretical description of the full spectrum requires one to have knowledge about the Green’s function propagators describing the time evolution of a Dy atom with the electron multi-configurational many body wave-function corresponding to the ground-state of Ho with one additional core hole. The time evolution involves fluorescence and Auger decays into bound and continuum states. These decays produce the tails of the spectrum and ultimately create the end-point of the spectrum that is influenced most by the mass of the neutrino.Using a combination of numerical methods as used in quantum chemistry (configuration interaction) and solid state physics (Green’s functions and renormalization group) we aim to achieve a numerical accuracy able to predict the mulitplet governed spectra of the core level decay with unprecedented precision. In order to achieve this we will include all possible local multiplets (shake-up and shake-down) as well as Auger and fluorescence yield decay of the excitations. We furthermore will consider the interaction of the local Ho 4f states with the electronic continuum of the host metal. We will develop the needed numerical methods to handle the many body correlations of both the ground-state as well as the excited states with sub-electron volt accuracy. We will furthermore provide an error estimate of the calculations indicating the maximal difference between the physical reality and calculated spectra.These calculations will firstly provide a detailed understanding of the electron capture resonances and their structure. Secondly, these calculations will provide information how much the end-point region is influenced by mulitplet excitations, extended fine-structure in the spectra due to multiple scattering events of Auger electrons in the host material and selection rules in the decay process related to the alignment of the magnetic moment of the 163Ho 4f shell and the 163Ho nucleus. The final aim is to provide a detailed understanding of the 163Ho electron capture spectrum needed for the accurate determination of the neutrino mass.

在此基础上，我们将从头计算预测163 Ho的量热电子俘获谱。从粒子物理学的角度来看，电子与质子的弱相互作用导致中子和电子中微子的产生在理论上是简单的。在中性原子中，当同样的相互作用发生时，更复杂的过程将伴随着原子核捕获电子。原子中的电子不是独立的，由于强烈的库仑力，一旦一个电子被捕获，所有电子都会反应。因此，Ho的量热测量光谱不是由分别来自3s到6s和3 p 1/2到5 p 1/2壳层的捕获事件的仅仅7个洛伦兹形状的峰给出的，而是出现了几个额外的具有涉及多重态结构的振动和振动结构。全谱的理论描述要求人们了解描述Dy原子与Ho基态电子多组态多体波函数随时间演化的绿色函数传播子。时间演化涉及荧光和俄歇衰变到束缚态和连续态。这些衰变产生了光谱的尾部，并最终产生了受中微子质量影响最大的光谱终点。（组态相互作用）和固态物理学（绿色函数和重整化群）我们的目标是达到一个数值精度，能够预测的多重支配的核心水平衰变的光谱，以前所未有的精度。为了实现这一点，我们将包括所有可能的本地多重态（shake-up和shake-down）以及俄歇和荧光产率衰减的激发。此外，我们将考虑本地Ho 4f态与主体金属的电子连续的相互作用。我们将开发所需的数值方法来处理许多机构的相关性的基态以及激发态亚电子伏特的精度。我们还将提供一个误差估计的计算表明物理现实和计算的光谱之间的最大差异。这些计算将首先提供一个详细的了解电子捕获共振和它们的结构。其次，这些计算将提供的信息有多少端点区域的影响，多重激发，扩展精细结构的光谱由于多个散射事件的俄歇电子在主机材料和选择规则的衰变过程中有关的磁矩的排列的163 Ho 4f壳和163 Ho核。最后的目的是提供一个详细的了解所需的中微子质量的准确测定的163 Ho电子捕获光谱。