2,252 research outputs found

    Predictions from the Fritzsch-Type Lepton Mass Matrices

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    We revisit the Fritzsch-type lepton mass matrix models confronted with new experiments for neutrino mixings. It is shown that the model is viable and leads to a rather narrow range of free parameters. Using empirical mixing information between νe\nu_e and νμ\nu_\mu, and between νμ\nu_\mu and ντ\nu_\tau, it is predicted that the mixing angle between nuenu_e and ντ\nu_\tau is in the range 0.04<U13<0.200.04<|U_{13}|<0.20, consistent with the CHOOZ experiment and the lightest neutrino mass is 0.0004<m1<0.00300.0004<m_1<0.0030 eV. The range of the effective mass measured in double beta decay is 0.002<0.0070.002<0.007 eV.Comment: Latex file with 13 pages, 6 eps file

    Burst Neutrinos from Nitrogen Flash

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    Neutrinos give a novel probe to explore deep interior of astrophysical objects, which otherwise is not accessible with optical observations; among notable examples are solar and supernova neutrinos. We show that there is a new class of strong neutrino emission from helium burning, N + alpha --> 18F gamma followed by beta decay 18F --> 18O + e+ + nu_e, that gives a maximum neutrino luminosity of 10^8 times the solar bolometric luminosity at the helium-core flash of a 1 M_sun star, whereas the flash is not observable by optical means. This means that the neutrino flux, of average energy of 0.382 MeV, will be 10% the solar CNO neutrino flux on Earth if the star is located at 10pc.Comment: Accepted to ApJ Letters. Replaced version with extended discussion. Some additional references adde

    Radiative Corrections to Neutrino Reactions off Proton and Deuteron

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    Radiative corrections are calculated for antineutrino proton quasielastic scattering, neutrino deuteron scattering, and the asymmetry of polarised neutron beta decay from which GA/GVG_{A}/G_{V} is determined. A particular emphasis is given to the constant parts that are usually absorbed into the coupling constants, and thereby those that appear in the processes that concern us are unambiguously tied among each other.Comment: Talk give at the 10th International Symposium on Particles, Strings and Cosmology (at Northeastern University, Boston, August 16-22, 2004

    Megaton Water Cerenkov Detectors and Astrophysical Neutrinos

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    Although formal proposals have not yet been made, the UNO and Hyper-Kamiokande projects are being developed to follow-up the tremendously successful program at Super-Kamiokande using a detector that is 20-50 times larger. The potential of such a detector to continue the study of astrophysical neutrinos is considered and contrasted with the program for cubic kilometer neutrino observatories.Comment: 4 pages Submitted to the Proceedings of the 2004 Neutrino Oscillation Workshop, Otranto Ital

    A Derivation of the Fermi Function in Perturbative Quantum Field Theory

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    We postulate that the Fermi function should be derived from the amplitude, not from the solution of the Dirac equation, in the quantum field theory. Then, we obtain the following results. 1, We give the amplitude and the width of the neutron beta decay, np+e+νˉen \to p + e^- + \bar \nu_e to one loop order. It is carried out by the Feynman parameter integration. 2, As the result, we find the terms which can be interpreted as the Fermi function expanded to order α\alpha. 3, We also give the same result using complex analysis. 4, We check that there are no such terms in the similar process, νˉe+pe++n\bar \nu_e + p \to e^+ + n. 5, We perform the Fermi function expanded to order α2\alpha^2 using complex analysis.Comment: 8 page

    Finite-Size Effect of Hadron Masses with Kogut-Susskind Quarks

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    We present numerical results and their analyses of finite-size effects of hadron masses for both quenched and full QCD calculations. We show that they are much larger for full QCD due to dynamical sea quarks and the associated breaking of Z(3)Z(3) symmetry. We also argue that finite-size effects are non-negligible even for the largest lattice size simulation currently being made for a very small quark mass. (talk at lattice93)Comment: 4 pages, compressed, uuencoded PostScript file(name:lat93.ps.Z