  A Symplectic Effective Field Theory that unveils the observed emergence of
symplectic symmetry in atomic nuclei is advanced. Specifically, starting from a
simple extension of the harmonic-oscillator Lagrangian, an effective field
theory applied against symplectic basis states is shown to yield a Hamiltonian
system with one fitted parameter. The scale of the system can be determined
self consistently as the ratio of the average volume of a nucleus assumed to be
spherical to its volume as determined by the average number of oscillator
quanta, which is stretched by the fact that the plane-wave solution satisfies
the equations of motion at every order without the need for perturbative
corrections. As an application of the theory, results for 20Ne, 22Ne and 22Mg
are presented that yield energy spectra, B(E2) values, and matter radii in good
agreement with experimentally measured results.
