Year: 2025
Type: preprint
Abstract: We investigate the residual energy distribution in the electron capture (EC) process of $^{159}$Dy, emphasizing the role of subthreshold atomic states, which have typically been omitted in conventional spectral analyses. By incorporating these energetically forbidden hole states into the spectral function $P(E)$, we demonstrate a significant enhancement - over an order of magnitude - in the EC rate near the zero-momentum neutrino emission region. This enhancement increases further with larger $Q$ values, contrary to standard expectations. Our analysis shows that $P(E)$ can be experimentally determined, resolving ambiguities near the endpoint and enabling new approaches to 'ultra-low $Q$ value' EC reactions for neutrino mass studies.
Source: arXiv (Cornell University)
Authors: Kishimoto, Tadafumi, Sato, Toru
Language: English
Topic: Neutrino Physics Research
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7078545197
Cites:
Cited by:
Related to: