Nuclear Physics in the Deuterium Atom
By trading 12 orders of magnitude in electron energy for roughly the same factor
in experimental precision, atomic measurements of some deuteron quantities can
compete with accelerator measurements. The deuteron matter radius, for example,
is most accurately determined by the isotope shift in the 1S-2S level splittings
of H and D. The precision of this determination is adequate to provide a window
on small relativistic corrections and meson-exchange currents in the deuteron,
which is unattainable in accelerator measurements. Hyperfine splittings in the
deuterium atom measure a charge-magnetic correlation in leading order, while the
physics of the sub-leading order is related to that of the Drell-Hearn-Gerasimov
sum rule. I will discuss these issues and give a brief overview of the atomic
physics involved.