Neutrino Mass, Electron Capture and the Shake-off Contributions

Abstract

Electron capture can determine the electron neutrino mass, while the beta decay of Tritium measures the electron antineutrino mass and the neutrinoless double beta decay observes the Majorana neutrino mass. Electron capture e. g. on 163Ho plus bound electron to 163Dy* plus neutrino can determine the electron neutrino mass from the upper end of the decay spectrum of the excited Dy*, which is given by the Q-Value minus the neutrino mass. The Dy* states decay by X-ray and Auger electron emissions. The total decay energy is measured in a bolometer. These excitations have been studied by Robertson and by Faessler et al.. In addition the daughter atom Dy can also be excited by moving in the capture process one electron into the continuum. The escape of these continuum electrons is automatically included in the experimental bolometer spectrum. Recently a method developed by Intemann and Pollock was used by DeRujula and Lusignoli for a rough estimate of this shake-off process for "s" wave electrons in capture on 163Ho. The purpose of the present work is to give a more reliable description of "s" wave shake-off in electron capture on Holmium. For that one needs very accurate atomic wave functions of Ho in its ground state and excited atomic wave functions of Dy* including a description of the continuum electrons. In the present approach the wave functions of Ho and Dy* are determined selfconsistently with the antisymmetrized relativistic Dirac-Hartree-Fock approach. The relativistic continuum electron wave functions for the ionized Dy* are obtained in the corresponding selfconsistent Dirac-Hartree-Fock-Potential. In this improved approach shake-off can hardly be seen after electron capture in 163Ho and thus can probably not affect the determination of the electron neutrino mass.

20 pages, 9 figures

References in corpus (8)

• Current Direct Neutrino Mass Experiments
• HOLMES - The Electron Capture Decay of 163Ho to Measure the Electron Neutrino Mass with sub-eV sensitivity
• Examination of the calorimetric spectrum to determine the neutrino mass in low-energy electron capture decay
• Electron Capture in 163Ho and Overlap plus Exchange Corrections and the Neutrino Mass
• Improved Description of One- and Two-Hole States after Electron Capture in 163 Holmium and the Determination of the Neutrino Mass
• Determination of the neutrino mass by electron capture in 163 Holmium and the role of the three-hole states in 163 Dysprosium
• The calorimetric spectrum of the electron-capture decay of ${}^{163}$Ho. The spectral endpoint region
• The calorimetric spectrum of the electron-capture decay of ${}^{163}$Ho. A preliminary analysis of the preliminary data

Cited by in corpus (9)

• Direct Measurements of Neutrino Mass
• ${}^{159}$Dy electron-capture: a strong new candidate for neutrino mass determination
• Ab initio calculation of the electron capture spectrum of 163Ho: Auger-Meitner decay into continuum states
• $\text{Ab initio}$ calculation of the calorimetric electron capture spectrum of ${}^{163}$Holmium: Intra-atomic decay into bound-states
• High-precision electron-capture $Q$ value measurement of ${}^{111}$In for electron-neutrino mass determination
• Most stringent bound on electron neutrino mass obtained with a scalable low temperature microcalorimeter array
• Overlap of electron shells in $\beta$ and double-$\beta$ decays
• First Calorimetric Measurement of Electron Capture in ${}^{193}$Pt with a Transition Edge Sensor
• Phenomenological Modeling of the ${}^{163}$Ho Calorimetric Electron Capture Spectrum from the HOLMES Experiment