  We explore the suggestion that the neutron lifetime puzzle might be resolved
by neutrons decaying into dark matter through the process, n \rightarrow
\chi\chi\chi, with \chi having a mass one third of that of the neutron. In
particular, we examine the consequences of such a decay mode for the properties
of neutron stars. Unlike an earlier suggested decay mode, in order to satisfy
the constraints on neutron star mass and tidal deformability, there is no need
for a strong repulsive force between the dark matter particles. This study
suggests the possibility of having hot dark matter at the core of the neutron
star and presents a possible mechanism of dark matter cooling, and examines the
possible signal of neutrons decaying in this way inside the neutron star right
after its birth.
