Nuclear Physics: the Study of Quark Chemistry?
Nuclear physics has been built on the fact that nuclei are well described as bound states of nucleons that are almost identical to the free proton and neutron. However, these baryons are known to be composites of quarks with extremely strong Quantum ChromoDynamic (QCD) interactions. Why are the nucleons in nuclei not significantly distorted from their free space structure? We show that the two principle features of QCD phenomenology account for this qualitatively and demonstrate it quantitatively by constructing two small nuclei directly in terms of quarks. Predictions from this model for the "EMC effect" in deep inelastic scattering of leptons on nuclei appear to be accurate. A dibaryon that does not have nuclear characteristics is also predicted, for which there is "almost" evidence. We conclude that the nucleon-nucleon potential and meson-exchange approaches to nuclear physics bear similarities to chemistry before the appreciation of the electronic structure of atoms, and that body-fixed models of nuclear structure in terms of quark exchanges may lead to deeper understanding in a fashion parallel to that whereby chemistry advanced beyond such concepts as electron affinity, electronegativity, etc.