A1 Journal article (refereed)
Spectral shapes of second-forbidden single-transition nonunique β decays assessed using the nuclear shell model (2024)

Ramalho, M., Suhonen, J., Neacsu, A., & Stoica, S. (2024). Spectral shapes of second-forbidden single-transition nonunique β decays assessed using the nuclear shell model. Frontiers in Physics, 12, Article 1455778. https://doi.org/10.3389/fphy.2024.1455778

JYU authors or editors

Publication details

All authors or editors: Ramalho, Marlom; Suhonen, Jouni; Neacsu, Andrei; Stoica, Sabin

Journal or series: Frontiers in Physics

eISSN: 2296-424X

Publication year: 2024

Publication date: 15/08/2024

Volume: 12

Article number: 1455778

Publisher: Frontiers Media

Publication country: Switzerland

Publication language: English

DOI: https://doi.org/10.3389/fphy.2024.1455778

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/97180

Additional information: Research Topic: Beta Decay: Current Theoretical and Experimental Challenges

Abstract

Experimental and theoretical studies of β electrons (electrons emitted in β−-decaytransitions) and their β-electron spectra have recently experienced a rapid expansion. These β spectral shapes have been used to study total β spectra of fission-product nuclei in the quest for explanation of the reactor-flux anomalies, and individual β transitions in search for β spectral shapes sensitive to the effective value of the weak axial coupling gA. In the former case the TAGS (total absorption gamma-ray spectroscopy) can be efficiently used to measure the total β spectral shapes and in the latter case dedicated measurements of the involved forbidden nonunique β transitions have been deployed. The fourth-forbidden nonunique decay transitions 113Cd(1/2+ g.s.) → 113In(9/2+ g.s.) and 115In(9/2+ g.s.) → 115Sn(1/2+ g.s.) represent theoretically and experimentally much-studied cases where the total β spectra consist of these single transitions. In these particular cases the TAGS method could be used to assess the effective value of gA. In the present work we have identified five more interesting cases where a total β spectrum consists of a single transition. These spectra correspond to second-forbidden nonunique transitions and are gA and/or sNME dependent, where sNME denotes the so-called small relativistic vector nuclear matrix element. These studies have been performed using the nuclear shell model with well established effective Hamiltonians. With this we target to β transitions that would potentially be of high interest for the TAGS and present and future dedicated β-spectrum experiments

Keywords: nuclear physics; particle physics; particles (matter); beta radiation; spectroscopy

Free keywords: beta decay; electron spectral shapes; nuclear matrix elements; nuclear shell model; nuclear structure; small relativistic matrix element; weak axial coupling

Contributing organizations

Ministry reporting: Yes

VIRTA submission year: 2024

Preliminary JUFO rating: 1