Axial-Vector Coupling Constant in Nuclei and Dense Matter

Mannque Rho (1)

1 IPHT - Institut de Physique Théorique - UMR CNRS 3681

The in-medium property of the axial-vector coupling constant $g_A$ in nuclei and dense baryonic matter is reformulated in terms of the recently constructed scale-invariant hidden local symmetric ($bs$HLS) Lagrangian. It is shown that unlike the pion decay constant that slides with the vacuum change induced by density, the axial-current constant $g_A$ remains unmodified up to high density relevant to compact stars in nuclear Gamow-Teller transitions (involving the space component of the axial current) whereas it gets strongly enhanced in axial-charge transitions (involving the time component of the axial current) as density nears nuclear matter density $n_0$ and stays more or less constant up to $\sim 6n_0$. The implications of these predictions on giant Gamow-Teller resonances in nuclei and on first-forbidden beta transitions (relevant to nuclear astrophysical processes) are discussed.

Domaines: Physique Nucléaire Théorique [nucl-th]

Mannque Rho. Axial-Vector Coupling Constant in Nuclei and Dense Matter. 2017. ⟨cea-01562873⟩