  Among composite-dark-matter scenarios, one of the simplest and most
predictive is that of O-helium (OHe) dark atoms, in which a lepton-like doubly
charged particle O is bound with a primordial helium nucleus, and is the main
constituent of dark matter. This model liberates the physics of dark matter
from many unknown features of new physics, and it demands a deep understanding
of the details of known nuclear and atomic physics, which are still somewhat
unclear in the case of nuclear interacting "atomic" shells. So far the model
has relied on the dominance of elastic scattering of OHe with the matter. In
view of the uncertainty in our understanding of OHe interaction with nuclei we
study the opposite scenario, in which inelastic nuclear reactions dominate the
OHe interactions with nuclei. We show that in this case all the OHe atoms bind
with extra He nuclei, forming doubly charged O-beryllium ions, which behave
like anomalous helium, causing potential problems with overabundance of
anomalous isotopes in terrestrial matter.
