On relation between unitary gauge and gauge given by $ξ$-limiting process

Abstract

It is shown that in general the gauge given by the limit of $ξ\to 0$ in $R_ξ$ gauge does not necessarily agree with the unitary gauge by examining the symmetry breaking of two steps from ${\rm SU(3) \otimes U(1)}_N$ to ${\rm SU(2) \otimes U(1)}_Y$ and then to ${\rm U(1)}_{em}$.

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