  The electron-capture decay of 180Re has been investigated to search for
oscillations in the decay probability as reported from a recent measurement at
GSI, Darmstadt. The production period was kept short compared to the reported
oscillation period. No such oscillation was observed, indicating that the
reported oscillations would not have been observable in a conventional
experiment with radioactive atoms in a solid environment but must have to do
with the unique conditions in the GSI experiment where hydrogen-like ions are
moving independently in a storage ring and decaying directly by a true two-body
decay to a long-lived (ground-) state. Our finding could restrict possible
theoretical interpretations of the oscillations.
