Manifestation of Hidden Symmetries in Baryonic Matter: From Finite Nuclei to Neutron Stars
Résumé
When hadron-quark continuity is formulated in terms of a topology change at a density higher than twice the nuclear matter density (n0), the core of massive compact stars can be described in terms of quasiparticles of fractional baryon charges, behaving neither like pure baryons nor like deconfined quarks. Hidden symmetries, both local gauge and pseudo-conformal (or broken scale), emerge and give rise both to the long-standing “effective gA∗≈ 1” in nuclear Gamow–Teller (GT) transitions at ≲ n0 and to the pseudo-conformal sound velocity vpcs2/c2 ≈ 1/3 at ≳ 3n0. It is suggested that what has been referred to, since a long time, as “quenched gA” in light nuclei reflects what leads to the dilaton-limit gADL = 1 at near the (putative) infrared fixed point of scale invariance. These properties are confronted with the recent observations in GT transitions and in astrophysical observations.
Mots clés
Hidden symmetries
nuclear matter
topology
density functional
Fermi-liquid theory
compact stars
nuclear matter: density
baryon: density: high
matter: density: high
fixed point: infrared
quark: deconfinement
nucleus: finite
baryon: charge
star: compact
topology: transition
velocity: acoustic
Gamow-Teller transition
hidden symmetry
quasiparticle
light nucleus
neutron star
quark hadron