Large Lorentz scalar and vector potentials in nuclei

In nonrelativistic models of nuclei, the underlying mass scales of low-energy quantum chromodynamics (QCD) are largely hidden. In contrast, the covariant formulations used in relativistic phenomenology manifest the QCD scales in nuclei through large Lorentz scalar and four-vector nucleon self-energies. The abundant and varied evidence in support of this connection and the consequences are reviewed.