  A dynamical mechanism of symmetry breaking in which gauge and matter fields
play an active role is proposed. It basically represents a covariant
generalization of the mechanism responsible for superconductivity, and provides
a {\em natural} mechanism of generation of mass which is not in conflict with
the present value of the cosmological constant. When applied to
SU(2)$\times$U(1) leads to exactly the same physics (Lagrangian density) as the
Standard Model but modifying {\em only} the Higgs sector. It also predicts the
appearance over all space of a classical scalar field as well as the existence
of density fluctuations. According to it, space would be filled with a
macroscopically large number of Higgs bosons which now appear as light, stable
scalar particles {\em decoupled} from ordinary matter and radiation. Therefore
they would play the same role as the Cooper pairs in superconductivity and
would be a natural candidate for dark matter.
