  Considering transformations in the basis of fundamental fields on a principal
fiber bundle, without modification in the space-time sector, we construct an
algebra GA, which we call Glashow algebra. The structure constants of this
algebra depend on a mixing angle. The Lagrangian of the gauge theory of
electroweak interactions without masses is obtained using a representation of
GA which is the transformed of the adjoint representation of the direct product
of SU(2) and U(1), and does not coincide with the adjoint representation of GA.
The mixing angle is automatically present in the theory if GA is used.
