  The collision of a high energy cosmic ray with a nucleon in the upper
atmosphere could produce long-lived heavy particles. Such particles would be
very penetrating, since the energy loss in matter scales as the inverse mass,
and could reach a neutrino telescope like IceCube from large zenith angles.
Here we study this possibility and focus on the long-lived stau of SUSY models
with a gravitino LSP. The signal would be a pair of muon-like parallel tracks
separated by 50 meters along the detector. We evaluate the background of muon
pairs and show that any events from zenith angles above 80 degrees could be
explained by the production of these heavy particles by cosmic rays.
