Mass Generation from Lie Algebra Extensions
  Applied to the electroweak interactions, the theory of Lie algebra extensions suggests a mechanism by which the boson masses are generated without resource to spontaneous symmetry breaking. It starts from a gauge theory without any additional scalar field. All the couplings predicted by the Weinberg-Salam theory are present, and a few others which are nevertheless consistent within the model. 
R. Aldrovandi, V. C. de Andrade, A. L. Barbosa, J. G. Pereira