Where Have All the Goldstone Bosons Gone?
  According to a commonly held view of spontaneously broken symmetry in gauge theories, troublesome Nambu-Goldstone bosons are effectively eliminated by turning into longitudinal modes of a massive vector meson. This note shows that this is not in fact a consistent view of the role of Nambu-Goldstone bosons in such theories. These particles necessarily appear as gauge excitations whenever they are formulated in a manifestly covariant gauge. The radiation gauge provides therefore the dual advantage of circumventing the Goldstone theorem and making evident the disappearance of these particles from the physical spectrum. 
G. S. Guralnik and C. R. Hagen
hep-th hep-ph