Englert-Brout-Higgs Mechanism in Nonrelativistic Systems
  We study the general theory of Englert-Brout-Higgs mechanism without assuming Lorentz invariance. In the presence of a finite expectation value of non-Abelian matter charges, gauging those symmetries always results in spontaneous breaking of spatial rotation. If we impose the charge neutrality by assuming a background with the opposite charges, the dynamics of the background cannot be decoupled and has to be fully taken into account. In either case, the spectrum is continuous as the gauge coupling is switched off. 
Haruki Watanabe, Hitoshi Murayama
hep-th cond-mat.other cond-mat.quant-gas cond-mat.supr-con hep-ph