Publication : t18/099

Abstract:
How the axial coupling constant gA in nuclear Gamow-Teller transitions described in shell model gets "quenched" to a universal constant close to 1 can be explained by nuclear correlations in Fermi-liquid fixed point theory using a scale-symmetric chiral Lagrangian supplemented with hidden local symmetric vector mesons. Contrary to what one might naively suspect -- and has been discussed in some circles, there is no fundamental quenching at nuclear matter density due to QCD condensates. When the density of many-body systems treated with the same Lagrangian increases beyond the density $n=n_{1/2}gsim 2n_0$ (where n0 is the normal nuclear matter density) at which skyrmions representing baryons fractionize to half-skyrmions, with the ρ meson driven toward the vector manifestation fixed point and a scalar meson σ driven to the dilaton-limit fixed point with the nucleons parity-doubled, the dense matter supports the "pseudo-conformal" sound velocity for $ngsim n_{1/2}$ while the trace of the energy momentum tensor remains non-vanishing. A plausible interpretation is that this signals the emergence of scale symmetry not explicitly present or hidden in QCD in the vacuum. The fundamental constant gA, unaffected by QCD condensates for n Année de publication : 2018
Preprint : arXiv:1804.00310
Langue : Anglais

Fichier(s) à télécharger :

publi.pdf