Shizue Echigo

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We present an analysis of atmospheric neutrino data from a 33.0 kiloton-year (535-day) exposure of the Super{Kamiokande detector. The data exhibit a zenith angle dependent decit of muon neutrinos which is inconsistent with expectations based on calculations of the atmospheric neutrino ux. Experimental biases and uncertainties in the prediction of neutrino(More)
Super-Kamiokande is the world's largest water Cherenkov detector, with net mass 50,000 tons. Earth's atmosphere, and the K2K long-baseline neutrino beam with high efficiency. These data provided crucial information for our current understanding of neutrino oscillations, as well as setting stringent limits on nucleon decay. In this paper, we describe the(More)
Analysis of the sterol fraction obtained from the Colombian Caribbean sponge Topsentia ophiraphidites revealed that this sponge is a rich source of C30 and C31 sterols. Among them, a new C31 sterol, named ophirasterol, was isolated, and its structure was established as (22E,24R)-24-(1-buten-2-yl)cholesta-5,22-dien-3beta-ol (1) by spectral means and(More)
The atmospheric neutrino ux ratio = e and its zenith angle dependence have been measured in the multi-GeV energy range using an exposure of 25.5 kiloton-years of the Super-Kamiokande detector. By comparing the data to a detailed Monte Carlo simulation, the ratio =e DATA ==e M C was measured to be 0:660:06stat:0:08sys:. In addition, a strong distortion in(More)
The atmospheric neutrino flux ratio ν µ /ν e and its zenith angle dependence have been measured in the multi-GeV energy range using an exposure of 25.5 kiloton-years of the Super-Kamiokande detector. By comparing the data to a detailed Monte Carlo simulation, the ratio (µ/e) DAT A /(µ/e) MC was measured to be 0.66 ± 0.06(stat.) ± 0.08(sys.). In addition, a(More)
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