The Higgs Mechanism in Heterotic Orbifolds
  We study spontaneous gauge symmetry breaking in the framework of orbifold compactifcations of heterotic string theory. In particular we investigate the electroweak symmetry breakdown via the Higgs mechanism. Such a breakdown can be achieved by continuous Wilson lines. Exploiting the geometrical properties of this scheme we develop a new technique which simplifies the analysis used in previous discussions. 
Stefan Forste, Hans Peter Nilles, Akin Wingerter