Y. Fukudaa, E. Ichiharaa Hayakawaa, K. Inouea, H. Ishinoa, Y. Itowa, T. Kajitaa, J. Kamedaa, S. Kasugaa, K. Kobayashia, Y. Kobayashia, Y. Koshioa, M. Miuraahttp://academic.research.microsoft.com/io.ashx?type=5&id=12566723&selfId1=0&selfId2=0&maxNumber=12&query=
A total of 614 upward through-going muons of minimum energy 1.6 GeV are observed by Super-Kamiokande during 537 detector live days. The measured muon flux is (1.74 ± 0.07(stat.) ± 0.02(sys.)) × 10−13cm−2s−1sr−1 compared to an expected flux of (1.97 ± 0.44(theo.)) × 10−13cm−2s−1sr−1. The absolute measured flux is in agreement with the prediction within the errors. However, the zenith angle dependence of the observed upward through-going muon flux does not agree with no-oscillation predictions. The observed distortion in shape is consistent with the �µ ↔ �� oscillation hypothesis with sin2 2� > 0.4 and 1 × 10−3 < �m2 < 1 × 10−1 eV2 at 90 % confidence level.