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

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.