A common scenario for an small vacuum energy and long lived super heavy   dark matter
  A toy model giving rise to long lived super heavy particles and an small vacuum density energy, of the order of the one measured in the present universe, is constructed. This model consists in hidden sector invariant under an $SU(2)_L$ gauge symmetry, whose masses are provided by the standard Higgs mechanism. It is assumed that the standard model particles are also charged under this interaction. The hidden fermions and the hidden Higgs are super-heavy, which mass values close to the GUT scale. In addition, there is an spontaneously broken U(1) chiral symmetry, giving rise to a pseudoscalar Goldstone boson which we refer as a "hidden axion". We model the vacuum energy of the universe as the potential energy of this pseudoscalar, and this fixes several scales of the model. In particular, it is shown that the interaction between the hidden and the ordinary sector is very weak, of the order of the gravitational one. The approach to the vacuum energy problem presented here is a quintessence like mechanism, in which it is assumed that the true vacuum density energy is zero for some unknown reason, except for the contribution of the light axion. As consequence of the weakness of this interaction, the hidden Higgs is long lived and may act as a super heavy component of the dark matter at present times. 
O. P. Santillan
hep-th astro-ph.HE hep-ph