Vetoing atmospheric neutrinos in a high energy neutrino telescope

We discuss the possibility to suppress downward atmospheric neutrinos in a high energy neutrino telescope. This can be achieved by vetoing the muon which is produced by the same parent meson decaying in the atmosphere. In principle, atmospheric neutrinos with energies E-nu > 10 TeV and a zenith angle up to 60 degrees can be vetoed with an efficiency of > 99%. Practical realization will depend on the depth of the neutrino telescope, on the muon veto efficiency, and on the ability to identify downward-moving neutrinos with a good energy estimation.