Measurement of atmospheric neutrino flux consistent with tau neutrino appearance

Phys Rev Lett. 2006 Oct 27;97(17):171801. doi: 10.1103/PhysRevLett.97.171801. Epub 2006 Oct 23.

Abstract

A search for the appearance of tau neutrinos from nu(mu) <--> nu(tau) oscillations in the atmospheric neutrinos has been performed using 1489.2 days of atmospheric neutrino data from the Super-Kamiokande-I experiment. A best fit tau neutrino appearance signal of 138+/-48(stat)-32(+15)(syst) events is obtained with an expectation of 78+/-26(syst). The hypothesis of no tau neutrino appearance is disfavored by 2.4 sigma.