Effective cosmological constant from TeV-scale physics: Simple   field-theoretic model
  Adopting the q-theory approach to the cosmological constant problem, a simple field-theoretic model is presented which generates an effective cosmological constant (remnant vacuum energy density) of the observed order of magnitude, \Lambda_{eff} \sim (meV)^4, if there exist new TeV-scale ultramassive particles with electroweak interactions. The model is simple, in the sense that it involves only a few types of fields and two energy scales, the gravitational energy scale E_{Planck}\sim 10^{15} TeV and the electroweak (new-physics) energy scale E_{ew}\sim 1-10 TeV. 
F.R. Klinkhamer
hep-th