  The mystery of the Dark energy is not just its smallness. The extreme fine
tuning of its density in the Early Universe such that it permits galaxy
formation before creating a new inflationary epoch is its other unexplained
aspect. Here we propose a model based on the very slow decay of a Super Heavy
Dark Matter (SDM), presumed candidate for the origin of the Ultra High Energy
Cosmic Rays (UHECRs). A small part of the remnants energy is in the form of a
scalar field which decoheres and behaves like a quintessence field. This model
does not need a special form for the potential and a simple ${\phi}^4$ theory
or an axion like scalar is enough. The equation of state of the Dark Energy
becomes very close to a cosmological constant and is very well consistent with
observations.
