2,440 research outputs found

    Probing Majorana neutrinos in rare K and D, D_s, B, B_c meson decays

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    We study lepton number violating decays of charged K, D, D_s, B and B_c mesons of the form M^+\to {M'}^-\ell^+\ell^+, induced by the existence of Majorana neutrinos. These processes provide information complementary to neutrinoless double nuclear beta decays, and are sensitive to neutrino masses and lepton mixing. We explore neutrino mass ranges m_N from below 1 eV to several hundred GeV. We find that in many cases the branching ratios are prohibitively small, however in the intermediate range m_\pi < m_N < m_{B_c}, in specific channels and for specific neutrino masses, the branching ratios can be at the reach of high luminosity experiments like those at the LHC-b and future Super flavor-factories, and can provide bounds on the lepton mixing parameters.Comment: 25 page

    Late-time Phase transition and the Galactic halo as a Bose Liquid: (II) the Effect of Visible Matter

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    In the previous work, we investigated the rotation curves of galaxies assuming that the dark matter consists of ultra light boson appearing in 'late time phase transition' theory. Generalizing this work, we consider the effect of visible matter and classify the types of rotation curves as we vary the fraction of the mass and extention of visible matter. We show that visible matter, in galaxies with flat rotation curves, has mass fraction 2%10% 2\% \sim 10\% and it is confined within the distance fraction 10%20% 10\% \sim 20\%.Comment: 10 pages, 10 figures included, to appear in Phys. Rev. D50,p365

    The Dropping of In-Medium Hadron Mass in Holographic QCD

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    We study the baryon density dependence of the vector meson spectrum using the D4/D6 system together with the compact D4 baryon vertex. We find that the vector meson mass decreases almost linearly in density at low density for small quark mass, but saturates to a finite non-zero value for large density. We also compute the density dependence of the η\eta\prime mass and the η\eta\prime velocity. We find that in medium, our model is consistent with the GMOR relation up to a few times the normal nuclear density. We compare our hQCD predictions with predictions made based on hidden local gauge theory that is constructed to model QCD.Comment: 20 pages, 7 figure

    Comments on Baryon Melting in Quark Gluon Plasma with Gluon Condensation

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    We consider a black hole solution with a non-trivial dilaton from IIB super gravity which is expected to describe a strongly coupled hot gauge plasma with non-vanishing gluon condensation present. We construct a rotating and moving baryon to probe the screening and phases of the plasma. Melting of the baryons in hot plasma in this background had been studied previously, however, we show that baryons melt much lower temperature than has been suggested previously.Comment: 3 figures, 12 page
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