How and How Much is ${g_A}$ {\it Fundamentally} Quenched in Nuclei?

Mannque Rho

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arXiv · 2212.05558

How and How Much is ${g_A}$ {\it Fundamentally} Quenched in Nuclei?

Mannque Rho

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Abstract

The superallowed Gamow-Teller transition in the doubly-magic-shell nucleus $^{100}$Sn and the high resolution spectral shape analysis in the fourth-forbidden nonunique transition in $^{115}$In indicate as much as $\sim 40\%$ {\it fundamental} quenching in the axial-current coupling constant $g_A$ in nuclei. This can be attributed to an effect of the trace anomaly in QCD "emerging" in nuclear medium. If confirmed, this would signal a major revamping to do in nuclear interactions consistent with chiral-scale symmetry in nuclear medium and a big impact on $0\nu$ and $\nu\nu$ double $\beta$ decays for BSM. I present an argument that such a big anomaly-induced quenching is incompatible with how hidden scale symmetry manifests in nuclear medium, A possible means to resolve this issue is discussed in terms of hidden scale symmetry permeating in baryonic matter from normal nuclear matter to massive compact-star matter.

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Mannque Rho. 2022-12-11. How and How Much is ${g_A}$ {\it Fundamentally} Quenched in Nuclei?. https://arxiv.org/abs/2212.05558

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