A1 Journal article (refereed)
Quenching of gA deduced from the β-spectrum shape of 113Cd measured with the COBRA experiment (2020)

COBRA collaboration. (2020). Quenching of gA deduced from the β-spectrum shape of 113Cd measured with the COBRA experiment. Physics Letters B, 800, Article 135092. https://doi.org/10.1016/j.physletb.2019.135092

JYU authors or editors

Publication details

All authors or editors: COBRA collaboration

Journal or series: Physics Letters B

ISSN: 0370-2693

eISSN: 1873-2445

Publication year: 2020

Volume: 800

Article number: 135092

Publisher: Elsevier

Publication country: Netherlands

Publication language: English

DOI: https://doi.org/10.1016/j.physletb.2019.135092

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/67073

Abstract

A dedicated study of the quenching of the weak axial-vector coupling strength gA in nuclear processes has been performed by the COBRA collaboration. This investigation is driven by nuclear model calculations which show that the β-spectrum shape of the fourfold forbidden non-unique decay of 113Cd strongly depends on the effective value of gA. Using an array of CdZnTe semiconductor detectors, 45 independent 113Cd spectra were obtained and interpreted in the context of three nuclear models. The resulting effective mean values are g‾A(ISM)=0.915±0.007, g‾A(MQPM)=0.911±0.013 and g‾A(IBFM-2)=0.955±0.022. These values agree well within the determined uncertainties and deviate significantly from the free value of gA. This can be seen as a first step towards answering the long-standing question regarding quenching effects related to gA in low-energy nuclear processes.

Keywords: nuclear physics; particle physics

Free keywords: 113Cd beta-decay; axial-vector coupling; gA quenching; spectrum-shape method; CdZnTe; COBRA

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Ministry reporting: Yes

Reporting Year: 2020

JUFO rating: 2