  It is conventionally taken for granted that the unitary gauge formulation of
quantum gauge field theory has the advantage of preservation unitarity because
only physical fields are involved but has the disadvantage of losing
renormalizability because of severe ultraviolet divergences due to vector meson
propagators. In this paper, we show how to handle the ultraviolet divergent
loops so that the physical amplitudes remain gauge invariant. One of the
consequences we arrive at is that ghost loops are needed to cancel the
divergences due to vector mesons and to give gauge invariant physical
amplitudes.
