3,698 research outputs found

    Neutrino Mass Matrix and Hierarchy

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    We build a model to describe neutrinos based on strict hierarchy, incorporating as much as possible, the latest known data, for Δsol\Delta_{sol} and Δatm\Delta_{atm}, and for the mixing angles determined from neutrino oscillation experiments, including that from KamLAND. Since the hierarchy assumption is a statement about mass ratios, it lets us obtain all three neutrino masses. We obtain a mass matrix, MνM_\nu and a mixing matrix, UU, where both MνM_\nu and UU are given in terms of powers of Λ\Lambda, the analog of the Cabibbo angle λ\lambda in the Wolfenstein representation, and two parameters, ρ\rho and κ\kappa, each of order one. The expansion parameter, Λ\Lambda, is defined by Λ2=m2/m3=(Δsol/Δatm)\Lambda^2 = m_2/m_3 = \surd (\Delta_{sol}/\Delta_{atm}) \approx 0.16, and ρ\rho expresses our ignorance of the lightest neutrino mass m1,(m1=ρΛ4m3m_1, (m_1 = \rho \Lambda^4 m_3), while κ\kappa scales s13s_{13} to the experimental upper limit, s13=κΛ20.16κs_{13} = \kappa \Lambda^2 \approx 0.16 \kappa. These matrices are similar in structure to those for the quark and lepton families, but with Λ\Lambda about 1.6 times larger than the λ\lambda for the quarks and charged leptons. The upper limit for the effective neutrino mass in double β\beta-decay experiments is 4×103eV4 \times 10^{-3} eV if s13=0s_{13} = 0 and 6×103eV6 \times 10^{-3} eV if s13s_{13} is maximal. The model, which is fairly unique, given the hierarchy assumption and the data, is compared to supersymmetric extension and texture zero models of mass generation.Comment: 8 pages, LaTex, This paper updates an earlier version by incorporating KamLAND dat

    Integrable Anisotropic Evolution Equations on a Sphere

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    V.V. Sokolov's modifying symmetry approach is applied to anisotropic evolution equations of the third order on the n-dimensional sphere. The main result is a complete classification of such equations. Auto-B\"acklund transformations are also found for all equations.Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

    European Cyber Security System

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    Nowadays computer networks are widely spread in all spheres of human life. That is why the problem of cyber security of mankind is of great importance. Today, the European Union makes efforts to guarantee network safety in Europe by means of increase its member states in power and international cooperation in cyber security, including non-member countries, to prevent cyber crimes. Striving to join the European Union, Ukraine is involved in the process of providing cyber security. This paper examines the main strategies of EU standards in cyber security to be followed by Ukraine as one of European countries
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