$g_{\mathrm{A}}$-sensitive $\beta$ spectral shapes in the mass $A=86-99$ region assessed by the nuclear shell model

Abstract

Recent years have witnessed an expanding interest in experimental studies of $\beta$ electrons (electrons emitted in ${\beta }^{-}$ decay transitions) and their energy distributions, the so-called $\beta$-electron spectra. These experiments are interested mainly in $\beta$ transitions with electron spectra sensitive to the effective value of the weak axial coupling $g_{\mathrm{A}}$. In the present paper we make an extensive search for $g_{\mathrm{A}}$ sensitive $\beta$ spectral shapes in the $A=86-99$ region using the nuclear shell model with the well established Hamiltonians $\text{glekpn}$ and $\text{jj45pnb}$, designed to render a good description of the spectroscopic properties of nuclei in this mass region. We have found eight ${\beta }^{-}$ decay transitions with various degrees of $g_{\mathrm{A}}$ sensitivity. Moreover, these transitions are also important in pinning down the value of the so-called small relativistic vector nuclear matrix element, sNME. In addition, some of the corresponding mother nuclei are important contributors to the antineutrino flux from nuclear reactors. All this means that the found $\beta$ transitions are potentially of great interest for future rare-events experiments.

10 pages, 3 figures

References in corpus (9)

• Status and Future of Nuclear Matrix Elements for Neutrinoless Double-Beta Decay: A Review
• Toward the discovery of matter creation with neutrinoless double-beta decay
• Value of the axial-vector coupling strength in $\beta$ and $\beta \beta$ decays: A review
• Impact of the quenching of $g_{\mathrm{A}}$ on the sensitivity of $0\nu \beta \beta$ experiments
• Second-forbidden nonunique ${\beta }^{-}$ decays of ${}^{24}$Na and ${}^{36}$Cl assessed by the nuclear shell model
• Exchange correction for allowed $\beta$-decay
• ${}^{113}$Cd $\beta$-decay spectrum and $g_{\mathrm{A}}$ quenching using spectral moments
• Array of Cryogenic Calorimeters to Evaluate the Spectral Shape of forbidden $\beta$-decays: the ACCESS project
• First measurements with a new $\beta$-electron detector for spectral shape studies

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