Vetoing atmospheric neutrinos in a high energy neutrino telescope

Abstract

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 $E_ν> 10$ TeV and zenith angle up to 60 degree 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.

Figures (3)

• Figure 1: Two body decay of the parent meson into muon and neutrino. The left figure displays the back-to-back kinematics in the meson center of mass (cm) frame. The right figure shows the momenta after Lorentz transformation into the laboratory frame.
• Figure 2: Unaccompanied vertical atmospheric $\downarrow$$\nu_{\mu}$ flux (upper); probability of accompaniment (lower) for seven depths. The grey curve is the fraction of $\downarrow$$\nu_{\mu}$ from $\pi$ decay.
• Figure 3: Veto probability as a function of zenith angle for 1800 and 3500 m.w.e.