Quenching of gA deduced from the β-spectrum shape of 113Cd measured with the COBRA experiment

Autor: E. Rukhadze, Juliane Volkmer, Christian Nitsch, I. Stekl, Julia Küttler, Yingjie Chu, R. Hodák, Kevin Kröninger, J. Tebrügge, R. Temminghoff, Thomas Quante, Claus Gößling, S. Zatschler, Kai Zuber, D. Gehre, Arne Heimbold, Jouni Suhonen, Christian Herrmann, Joel Kostensalo, Lucas Bodenstein-Dresler
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Physics Letters B, Vol 800, Iss, Pp-(2020)
ISSN: 0370-2693
Popis: A dedicated study of the quenching of the weak axial-vector coupling strength $g_{\rm A}$ in nuclear processes has been performed by the COBRA collaboration. This investigation is driven by nuclear model calculations which show that the $\beta$-spectrum shape of the fourfold forbidden non-unique decay of $^{113}$Cd strongly depends on the effective value of $g_{\rm A}$. Using an array of CdZnTe semiconductor detectors, 45 independent $^{113}$Cd spectra were obtained and interpreted in the context of three nuclear models. The resulting effective mean values are $\bar{g}_{\rm A}(\text{ISM}) = 0.915 \pm 0.007$, $\bar{g}_{\rm A}(\text{MQPM}) = 0.911 \pm 0.013$ and $\bar{g}_{\rm A}(\text{IBFM-2}) = 0.955 \pm 0.022$. These values agree well within the determined uncertainties and deviate significantly from the free value of $g_{\rm A}$. This can be seen as a first step towards answering the long-standing question regarding quenching effects related to $g_{\rm A}$ in low-energy nuclear processes.
Comment: 12 pages, 11 figures
Databáze: OpenAIRE
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