A4 Article in conference proceedings
Total β-electron spectra of 214Pb and 214Bi (2024)

Ramalho, M., & Suhonen, J. (2024). Total β-electron spectra of 214Pb and 214Bi. In O. Civitarese, R. Hodak, J. Suhonen, & I. Stekl (Eds.), Workshop on the Calculation of Double-Beta-Decay Matrix Elements : MEDEX’23 (Article 020015). American Institute of Physics. AIP Conference Proceedings, 3138. https://doi.org/10.1063/5.0214181

JYU authors or editors

Publication details

All authors or editors: Ramalho, Marlom; Suhonen, Jouni

Parent publication: Workshop on the Calculation of Double-Beta-Decay Matrix Elements : MEDEX’23

Parent publication editors: Civitarese, Osvaldo; Hodak, Rastislav; Suhonen, Jouni; Stekl, Ivan

Place and date of conference: Prague, Czech Republic, 4.-8.9.2023

eISBN: 978-0-7354-4944-2

Journal or series: AIP Conference Proceedings

ISSN: 0094-243X

eISSN: 1551-7616

Publication year: 2024

Publication date: 18/09/2024

Number in series: 3138

Article number: 020015

Publisher: American Institute of Physics

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1063/5.0214181

Persistent website address: https://doi.org/10.1063/5.0214181

Publication open access: Not open

Publication channel open access: 

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/97631

Abstract

Beta electrons (electrons emitted in β decays) are a common background in rare-events experiments searching for beyond-thestandard-model physics in double beta decays, in dark-matter detection, etc. One particular culprit for the background events are the 220,222Rn radioactive chains leading to β − decays of 212,214Pb and 212,214Bi, common contaminants in the rare-events experiments. We have computed the total β-electron spectra of these decays using a state-of-the-art β-decay theory. The β decays involve numerous first-forbidden non-unique transitions depending strongly on the wave functions of the decay mother and daughter nuclei through the many involved nuclear matrix elements (NME). These NME have been computed by using the interacting shell model (ISM) with the khpe effective Hamiltonian. This Hamiltonian leads to a nice description of the energy spectra of the involved nuclei. We are able to reproduce the measured branching ratios of all the decay transitions by adopting the small relativistic NME (sNME) as a fit parameter. Here we report detailed results for the decays of 214Pb and 214Bi. We are confident that these calculations help the present and future rare-events experiments better identify their β-electron backgrounds stemming from the radon β-decay chains.

Keywords: nuclear physics; particle physics; beta radiation; dark matter

Free keywords: beta decay; electron spectral shapes; total electron spectra

Contributing organizations

Ministry reporting: Yes

VIRTA submission year: 2024

Preliminary JUFO rating: 1