A Note on the Gauge Group of the Electroweak Interactions
  We propose a three-fold covering of the group ${U}(2)$ as a gauge group for the electroweak interactions for the purpose of describing fields with integer and fractional electric charges with respect to the residual electromagnetic gauge group after a spontaneous breaking of the gauge symmetry. In a more general scheme we construct a three-fold covering of ${U} (n)$ and consider for the case $n=2$ several representations which are used in the construction of a model of the electroweak interactions in a subsequent paper. 
V. Rizov and I. Vitev