Gauge model with extended field transformations in Euclidean space

An SO(4) gauge-invariant model with extended field transformations is examined in four-dimensional Euclidean space. The gauge field is (A(mu))(alpha beta) = 1 2t(mu v lambda) (M-v lambda)(alpha beta), M-v lambda are the SO(4) generators in the fundamental representation. The SO(4) gauge indices also participate in the Euclidean space SO(4) transformations giving the extended field transformations. We provide the decomposition of the reducible field t(mu v lambda) in terms of fields irreducible under SO(4). The SO(4) gauge transformations for the irreducible fields mix fields of different spin. Reducible matter fields are introduced in the form of a Dirac field in the fundamental representation of the gauge group and its decomposition in terms of irreducible fields is also provided. The approach is shown to be applicable also to SO(5) gauge models in five-dimensional Euclidean space.