  First observation of (anti)deuterons in deep inelastic ep scattering (DIS)
measured with the ZEUS detector at HERA is reported. The production rate of
deuterons is higher than that of antideuterons. However, no asymmetry in the
production rate of protons and antiprotons was found. The (anti)deuteron yield
is approximately three orders of magnitude smaller than that of (anti)protons,
which is consistent with the world measurements.
