Chiral Symmetry and Meson-Exchange Currents

The meson-exchange current in nuclei, a long-standing problem in nuclear physics, is described in modern theory of strong interactions, namely, QCD expressed in terms of effective chiral Lagrangian field theory. Some old results are given a modern interpretation and some new results are predicted. Among the topics treated are an accurate calculation of the radiative np capture process at thermal energy, the enhanced axial charge transition in heavy nuclei, Brown-Rho (BR) scaling in dense medium induced by vacuum changes, dropping meson masses and "mended symmetry" in relativistic heavy-ion processes and the link between the physics of dilute and dense hadronic systems through a mapping of effective chiral Lagrangians to Landau Fermi-liquid theory.