Upper Limit on the Diffuse $\nu_\mu$ Flux with the ANTARES Telescope

Abstract

A search for very-high energy cosmic muon neutrinos from unresolved sources is presented using data collected by the ANTARES neutrino telescope. Data corresponding to 334 days of equivalent live time show that the observed number of events is compatible with the expected number of background events. A 90% c.l. upper limit on the diffuse $\nu_\mu$ flux is set at $E^2\Phi_{90%} = 5.3 \times 10^{-8} \ \mathrm{GeV\ cm^{-2}\ s^{-1}\ sr^{-1}} $ in the energy range 20 TeV -- 2.5 PeV.