BRST symmetry of $SU\!(2)$ Yang-Mills theoryin Cho-Faddeev-Niemi decomposition.

We determine the nilpotent BRST and anti-BRST transformations for the Cho-Faddeev-Niemi variables for the $SU\!(2)$ Yang-Mills theory based on the new interpretation given in a previous paper of the Cho-Faddeev-Niemi decomposition. This gives a firm ground for performing the BRST quantization of the Yang-Mills theory written in terms of the Cho-Faddeev-Niemi variables. We propose also a modified version of the new maximal Abelian gauge which could play an important role in the reduction to the original Yang-Mills theory. [ABSTRACT FROM AUTHOR]