We present an analysis of atmospheric neutrino data from a 33.0 kton yr (535-day) exposure of the Super-Kamiokande detector. The data exhibit a zenith angle dependent deficit of muon neutrinos which is inconsistent with expectations based on calculations of the atmospheric neutrino flux. Experimental biases and uncertainties in the prediction of neutrino fluxes and cross sections are unable to explain our observation. The data are consistent, however, with two-flavor n m $ n t oscillations with sin 2 2u . Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the upper atmosphere. Production of electron and muon neutrinos is dominated by the processes p 1 ! m 1 1 n m followed by m 1 ! e 1 1 n m 1 n e (and their charge conjugates) giving an expected ratio 1562 0031-9007͞98͞81(8)͞1562(6)$15.00
Solar neutrino measurements from 1258 days of data from the Super-Kamiokande detector are presented [? ]. The measurements are based on recoil electrons in the energy range 5.0-20.0 MeV. The measured solar neutrino flux is 2.32 ± 0.03 (stat.) +0.08 −0.07 (sys.) ×10 6 cm −2 s −1 , which is 45.1 ± 0.5 (stat.) +1.6 −1.4 (sys.)% of that predicted by the BP2000 SSM. The day vs night flux asymmetry (Φn − Φ d )/Φaverage is 0.033 ± 0.022 (stat.) +0.013 −0.012 (sys.). The recoil electron energy spectrum is consistent with no spectral distortion (χ 2 /d.o.f. = 19.0/18). The seasonal variation of the flux is consistent with that expected from the eccentricity of the Earth's orbit (χ 2 /d.o.f. = 3.7/7). For the hep neutrino flux, we set a 90% C.L. upper limit of 40 × 10 3 cm −2 s −1 , which is 4.3 times the BP2000 SSM prediction.22 This preprint is almost identical to the report submitted to Physical Review Letter. We have added to this preprint a few tables of
LiteBIRD is a next-generation satellite mission to measure the polarization of the cosmic microwave background (CMB) radiation. On large angular scales the B-mode polarization of the CMB carries the imprint of primordial gravitational waves, and its precise measurement would provide a powerful probe of the epoch of inflation. The goal of LiteBIRD is to achieve a measurement of the characterizing tensor to scalar ratio r to an uncertainty of δr = 0.001. In order to achieve this goal we will employ a kilopixel superconducting detector array on a cryogenically cooled sub-Kelvin focal plane with an optical system at a temperature of 4 K. We are currently considering two detector array options; transition edge sensor (TES) bolometers and microwave kinetic inductance detectors (MKID). In this paper we give an overview of LiteBIRD and describe a TES-based polarimeter designed to achieve the target sensitivity of 2 µK·arcmin over the frequency range 50 to 320 GHz.
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