8,277 research outputs found

    Formulations of spin 1 resonances in the chiral lagrangian

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    Equivalence of the hidden local symmetry formulation with non-minimal interactions and the anti-symmetric tensor field method of ρ\rho and a1a_1 mesons in the chiral lagrangian is shown by using the auxiliary field method. Violation of the KSRF I relation, which becomes important in the application of chiral lagrangian to {\em non QCD-like} technicolor models can be parametrized by non-minimal coupling in the hidden local symmetry formalism keeping low energy theorem of hidden local symmetry. We also obtain explicit correspondence of parameters in both formulations.Comment: 14 pages, late

    Higgs Doublets as Pseudo Nambu-Goldstone Bosons in Supersymmetric E_6 Unification

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    The idea to have Higgs doublets as pseudo Nambu-Goldstone (PsNG) multiplet is examined in the framework of supersymmetric E_6 unified theory. We show that extra PsNG multiplets other than the expected Higgs doublets necessarily appear in the E_6 case. If we demand that the extra PsNG multiplets neither disturb the gauge coupling unification nor make the color gauge coupling diverge before unification occurs, only possibility for the extra PsNG is 10+\bar{10} of SU(5). This is realized when the symmetry breaking E_6 \to SO(10) occurs in the \phi(27)+\phi(\bar{27}) sector while E_6 \to SU(4)_C\times SU(2)_L\times U(1)\times U(1) in the \Sigma(78) sector. The existence of 10+\bar{10} multiplets with mass around 1 TeV is therefore a prediction of this E_6 PsNG scenario. Implication of their existence on the proton decay is also discussed.Comment: 16 pages, no figures, LaTeX(PTPTeX style

    Sterile Neutrinos in a Grand Unified Model

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    The recent experimental results indicating the neutrino oscillations may strongly suggest that at least one more light neutrino species is required in order to reconcile the existing data. In the simple GUT frameworks, this fact seems difficult to preserve the parallelism between quarks and leptons. In this letter, we investigate an SO(10) grand unified model with a pair of extra generations in addition to the known three ones. Using the GUT relations, the obtained neutrino mass matrix naturally indicates that one of the SU(2) singlet (sterile) neutrino is very light and has large mixing with muon neutrino, which can explain the atmospheric neutrino anomaly, and the hot dark matter neutrino is also provided. The solar neutrino problem can be solved by the mixing with muon neutrino consistently with quark mixing, namely, the Cabibbo angle.Comment: 15 pages, 5 eps figure

    A Signal for Technicolor?

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    We propose an interpretation for the (llˉγγ, Mγγ=60GeVl\bar l\gamma \gamma ,\ M_{\gamma \gamma }=60{\rm GeV}) events, which have recently been reported by L3 group at LEP. This may be a first signal of `Technicolor' theory.Comment: 5pages, two Figures not included, phyzzx.te

    E_6 Unification with Bi-Large Neutrino Mixing

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    A scenario of SO(10) grand unified theory (GUT) proposed by one of the authors is extended to E_6 unification. This gives realistic quark and lepton mass matrices. In neutrino sector, the model reproduces large mixing angle (LMA) MSW solution as well as large mixing angle for atmospheric neutrino anomaly. In this model, right-handed down quark and left-handed lepton of the first and second generation belong to a single multiplet 27. This causes natural suppression of flavor changing neutral current(FCNC).Comment: 23 pages, V2:published versio

    Neutrino Mass Matrix Predicted From Symmetric Texture

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    Within the framework of grand unified theories, we make full analysis of symmetric texture to see if such texture can reproduce large neutrino mixings, which have recently been confirmed by the observed solar and atmospheric neutrino oscillation experiments. It is found that so-called symmetric texture with anomalous U(1) family symmetry with Froggatt-Nielsen mechanism does not provide a natural explanation of two large mixing angles. On the contrary we should adopt "zero texture" which have been extensively studied by many authors and only this scenario can reproduce two large mixing angles naturally. Under such "zero texture" with minimal symmetric Majorana matrix, all the neutrino masses and mixing angles, 6 quantities, are expressed in terms of up-quark masses, mt,mc,mum_t,m_c,m_u with two adjustable parameters. This provides interesting relations among neutrio mixing angles, tan22θ12144mcmttan22θ23cos2θ23,sin2θ134mcmtsin2θ23cos2θ12\tan^2 2\theta_{12} \simeq \frac{144m_c}{m_t} \tan^2 2\theta_{23} \cos^2 \theta_{23}, \quad \sin^2 \theta_{13} \simeq \frac{4m_c}{m_t}\sin^2 \theta_{23} \cos^2 \theta_{12}. Thus Ue3|U_{e3}| is predicted to lie within the range 0.010.060.01-0.06. Also absolute masses of three neutrinos are predicted almost uniquely. This is quite in contrast to the case where bi-large mixings come from the charged lepton sector with non-symmetric mass matrix, which does not provide the information of neutrino masses.Comment: 23 pages, latex, 15 figures. Preprint version contains "low resolution" figures to reduce the size of overall postscript file. Please contact authors to obtain the high resolution versio

    Neutrino Bi-Large Mixings and Family

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    After a brief review of quark-lepton relations in grand unified theories (GUT), we show that the Pati-Salam relation with only one type of Higgs field configuration with "four zero symmetric texture" can reproduce two large neutrino mixings as well as observed mass differences. This is quite in contrast to the case of SU(5) where bi-large mixings essentially come from the charged lepton sector with non-symmetric charged lepton mass matrix.Comment: 6 pages, latex, uses ws-procs9x6.cls. Talk presented by Bando at 4th Workshop on Neutrino Oscillations and their Origin (NOON2003), Kanazawa, Japan, 10-14 Feb 2003. To appear in the proceeding
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