Vacuum Nucleon Loops and Naturalness
  Phenomenological studies support the applicability of naturalness and naive dimensional analysis to hadronic effective lagrangians for nuclei. However, one-baryon-loop vacuum contributions in renormalizable models give rise to unnatural coefficients, which indicates that the quantum vacuum is not described adequately. The effective lagrangian framework accommodates a more general characterization of vacuum contributions without reference to a Dirac sea of nucleons. 
R. J. Furnstahl (Ohio State), Brian D. Serot (Indiana), Hua-Bin Tang   (Minnesota)