What "quenches" ${g_A}$ in nuclei ?

TL;DR

This paper explores how hidden scale symmetry and a dilaton influence nuclear correlations and the effective axial coupling $g_A$, proposing a connection to the pseudo-conformal sound speed in dense nuclear matter and suggesting experimental tests in $^{100}$Sn.

Contribution

It introduces a novel mechanism involving hidden scale symmetry and a dilaton to explain the quenching of $g_A$ in nuclei and links it to high-density nuclear matter properties.

Findings

Proposes a connection between scale symmetry and $g_A$ quenching.

Suggests the pseudo-conformal sound speed in dense matter.

Recommends precision measurements in $^{100}$Sn for validation.

Abstract

The answer is found in the way the hidden scale symmetry involving a dilaton emerges in strong nuclear correlations in nuclear matter. It is suggested that the same mechanism is at the origin at higher densities of the sound speed converging in the core of massive compact stars to what could be called ``pseudo-conformal sound speed" $v_s^2/c^2\approx 1/3$. A precision measurement of the superallowed Gamow-Teller transitions in the doubly magic nucleus $^{100}$Sn is suggested to confirm or falsify this prediction. It could also lead to the possible determination of genuine ``fundamental renormalization" of $g_A$ in nuclear medium.