Ultra High Energy Tau Neutrino Search in IceCube

The cubic kilometer scale IceCube detector is currently the worldʼs largest neutrino telescope operating in the deep ice at the South Pole. Using the data taken with its partial 22-string detector in 2007–2008, we searched for ultra-high energy (UHE) tau neutrinos from neutrino oscillations over cosmological scale baselines. With the currently developed method we set a sensitivity to the flux of all flavor neutrinos of extra-terrestrial origin as (90% C.L.) from 340 TeV to 200 PeV for 200 live days of data.