Here is another collaboration page, looking for dark matter in the form of a "second type of neutron."
https://neutronoscillationgrouputk.wordpress.com/2017/02/05/neutron-mirror-neutron-oscillation/ Instead of the antineutron, they focus on mirror-matter and the mirror-neutron. If this collaboration did not include the well-respected Oak Ridge National Laboratory, it is likely that the conclusions would be called Sci-Fi. Since ORNL has the largest neutron generator in the world, it is expected that rather soon, experiments will indeed characterize the mirror-neutron or else debunk the possibility. This is certainly Nobel Prize category research. Of course, they did not mention LENR here, and why should they? ... so it is a further stretch for LENR proponents to suggest that hydrogen would be transformed into a mirror-neutron within a metal lattice. Nevertheless, this is a provocative and elegant answer to several issues. As it turns out, the entire category of "antimatter" could be mislabeled to the extent that it should only apply to charged particles and the ability to have an unambiguous polarity change. There would be no neutral antimatter and the species formerly called an antineutron would possibly be a mirror neutron. A good case (but preliminary)is being made in several physics Labs around the World, involving the characterization of a dark matter particle which is both common and related to the neutron, but sterile and slightly lower in mass. In fact, it appears that about 1% of any neutron beam from any neutron generator(planned or unplanned) will consist of this particle, which seems to oscillate back and forth (as with neutrino oscillation). It has been called an X-particle, but it could actually be antimatter, or the equally exotic "mirror matter". As an uncharged particle it does not normally annihilate with matter but when it does, only muons are seen - never gamma photons. It is more like a mirror image neutron than what we expect of antimatter, but it seems to consist of antiquarks.
