  It was recently proposed that the disagreement in the experimental
measurements of the lifetime of the neutron might be eradicated if the neutron
decays to particles responsible for the dark matter in the Universe. In this
paper we construct a proto- type self-interacting dark matter model which,
apart from reproducing the correct relic abundance, resolves all small-scale
problems of the $\Lambda$CDM paradigm. The theory is compatible with all
present cosmological observations and astrophysical bounds.
