The recent RIKEN experiment on the quenched gA in the superallowed Gamow-Teller transition from 100Sn indicates the role of scale anomaly encoded in the anomalous dimension βof the gluonic stress tensor Tr G2μν. This observation provides support to the notion of hidden scale symmetry emerging by strong nuclear correlations with an infrared (IR) fixed point realized—in the chiral limit—in the Nambu—Goldstone mode. We suggest there is an analogy in the way scale symmetry manifests in a nuclear medium to the continuity from the unitarity limit at low density (in light nuclei) to the dilaton limit at high density (in compact stars). In between the limits, say, at normal nuclear matter density, the symmetry is not visible, hence hidden.

DOI: 10.1103/PhysRevLett.125.142501


Phys. Rev. Lett. 125, 142501 (2020)