269 research outputs found

    Type II Seesaw Dominance in Non-supersymmetric and Split Susy SO(10) and Proton Life Time

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    Recently type II seesaw dominance in a supersymmetric SO(10) framework has been found useful in explaining large solar and atmospheric mixing angles as well as larger values of theta13theta_{13} while unifying quark and lepton masses. An important question in these models is whether there exists consistency between coupling unification and type II seesaw dominance. Scenarios where this consistency can be demonstrated have been given in a SUSY framework. In this paper we give examples where type II dominance occurs in SO(10) models without supersymmetry but with additional TeV scale particles and also in models with split-supersummetry. Grand unification is realized in a two-step process via breaking of SO(10) to SU(5) and then to a TeV scale standard model supplemented by extra fields and an SU(5) Higgs multiplet 15H{15}_H at a scale about 101210^{12} GeV to give type-II seesaw. The predictions for proton lifetime in these models are in the range τp0=2×1035\tau_p^0 = 2\times 10^{35} yrs. to τp0=6×1035\tau_p^0 = 6\times 10^{35} yrs.. A number of recent numerical fits to GUT-scale fermion masses can be accommodated within this model.Comment: 7 pages LaTeX, 3 figures, related areas: hep-ex, hep-th, astro-ph; Reference added, typo corrected, version to appear in Physical Review

    Sensitivity of T2KK to the non-standard interaction in propagation

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    Assuming only the non-zero electron and tau neutrino components ϵee\epsilon_{ee}, ϵeτ\epsilon_{e\tau}, ϵττ\epsilon_{\tau\tau} of the non-standard matter effect and postulating the atmospheric neutrino constraint ϵττ=ϵeτ2/(1+ϵee)\epsilon_{\tau\tau}=|\epsilon_{e\tau}|^2/(1+\epsilon_{ee}), we study the sensitivity to the non-standard interaction in neutrino propagation of the T2KK neutrino long-baseline experiment. It is shown that T2KK can constrain the parameters ϵee1|\epsilon_{ee}|\lesssim 1, ϵeτ0.2|\epsilon_{e\tau}|\lesssim 0.2. It is also shown that if ϵeτ|\epsilon_{e\tau}| and θ13\theta_{13} are large, then T2KK can determine the Dirac phase and the phase of ϵeτ\epsilon_{e\tau} separately, due to the information at the two baselines. We also provide an argument that the components ϵαμ|\epsilon_{\alpha\mu}| (α=e,μ,τ)(\alpha=e,\mu,\tau) must be small for the disappearance oscillation probability to be consistent with high-energy atmospheric neutrino data, which justifies our premise that these quantities are negligible.Comment: 29 pages, 25 figures, uses revtex4-1. Several places including typos revised. New references adde

    Natural Diagonal Riemannian Almost Product and Para-Hermitian Cotangent Bundles

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    We obtain the natural diagonal almost product and locally product structures on the total space of the cotangent bundle of a Riemannian manifold. We find the Riemannian almost product (locally product) and the (almost) para-Hermitian cotangent bundles of natural diagonal lift type. We prove the characterization theorem for the natural diagonal (almost) para-K\"ahlerian structures on the total spaces of the cotangent bundle.Comment: 10 pages, will appear in Czechoslovak Mathematical Journa

    A Unified Algebraic Approach to Classical Yang-Baxter Equation

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    In this paper, the different operator forms of classical Yang-Baxter equation are given in the tensor expression through a unified algebraic method. It is closely related to left-symmetric algebras which play an important role in many fields in mathematics and mathematical physics. By studying the relations between left-symmetric algebras and classical Yang-Baxter equation, we can construct left-symmetric algebras from certain classical r-matrices and conversely, there is a natural classical r-matrix constructed from a left-symmetric algebra which corresponds to a parak\"ahler structure in geometry. Moreover, the former in a special case gives an algebraic interpretation of the ``left-symmetry'' as a Lie bracket ``left-twisted'' by a classical r-matrix.Comment: To appear in Journal of Physics A: Mathematical and Theoretica

    Special symplectic Lie groups and hypersymplectic Lie groups

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    A special symplectic Lie group is a triple (G,ω,)(G,\omega,\nabla) such that GG is a finite-dimensional real Lie group and ω\omega is a left invariant symplectic form on GG which is parallel with respect to a left invariant affine structure \nabla. In this paper starting from a special symplectic Lie group we show how to ``deform" the standard Lie group structure on the (co)tangent bundle through the left invariant affine structure \nabla such that the resulting Lie group admits families of left invariant hypersymplectic structures and thus becomes a hypersymplectic Lie group. We consider the affine cotangent extension problem and then introduce notions of post-affine structure and post-left-symmetric algebra which is the underlying algebraic structure of a special symplectic Lie algebra. Furthermore, we give a kind of double extensions of special symplectic Lie groups in terms of post-left-symmetric algebras.Comment: 32 page

    Distillation of Liquid Xenon to Remove Krypton

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    A high performance distillation system to remove krypton from xenon was constructed, and a purity level of Kr/Xe = 3×1012\sim 3 \times 10^{-12} was achieved. This development is crucial in facilitating high sensitivity low background experiments such as the search for dark matter in the universe.Comment: 15 pages, 11 figure

    Status of atmospheric neutrino(mu)<-->neutrino(tau) oscillations and decoherence after the first K2K spectral data

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    We review the status of nu_mu-->nu_tau flavor transitions of atmospheric neutrinos in the 92 kton-year data sample collected in the first phase of the Super-Kamiokande (SK) experiment, in combination with the recent spectral data from the KEK-to-Kamioka (K2K) accelerator experiment (including 29 single-ring muon events). We consider a theoretical framework which embeds flavor oscillations plus hypothetical decoherence effects, and where both standard oscillations and pure decoherence represent limiting cases. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at 1 sigma (and d.o.f.=1) as: Delta m^2=(2.6 +- 0.4)x10^{-3} eV^2 and sin^2(2theta)=1.00+0.00-0.05. As compared with standard oscillations, the case of pure decoherence is disfavored, although it cannot be ruled out yet. In the general case, additional decoherence effects in the nu_mu-->nu_tau channel do not improve the fit to the SK and K2K data, and upper bounds can be placed on the associated decoherence parameter. Such indications, presently dominated by SK, could be strengthened by further K2K data, provided that the current spectral features are confirmed with higher statistics. A detailed description of the statistical analysis of SK and K2K data is also given, using the so-called ``pull'' approach to systematic uncertainties.Comment: 18 pages (RevTeX) + 12 figures (PostScript

    Measurement of the cross-section and forward-backward charge asymmetry for the b and c-quark in e+e- annihilation with inclusive muons at sqrt(s) = 58 GeV

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    We have studied inclusive muon events using all the data collected by the TOPAZ detector at sqrt(s)=58 GeV with an integrated luminosity of 273pb-1. From 1328 inclusive muon events, we measured the ratio R_qq of the cross section for qq-bar production to the total hadronic cross section and forward-backward asymmetry A^q_FB for b and c quarks. The obtained results are R_bb = 0.13+-0.02(stat)+-0.01(syst), R_cc = 0.36+-0.05(stat)+-0.05(syst), A^b_FB = -0.20+-0.16(stat)+-0.01(syst) and A^c_FB = -0.17+-0.14(stat)+-0.02(syst), in fair agreement with a prediction of the standard model.Comment: To be published in EPJ C. 24 pages, 12 figure

    K0(K0ˉ)K^0(\bar{K^0}) Production in Two-Photon Processes at TRISTAN

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    We have carried out an inclusive measurement of K0(K0ˉ)K^0(\bar{K^0}) production in two-photon processes at TRISTAN. The mean s\sqrt{s} was 58 GeV and the integrated luminosity was 199 pb1^{-1}. High-statistics KsK_s samples were obtained under such conditions as no-, anti-electron, and remnant-jet tags. The remnant-jet tag, in particular, allowed us, for the first time, to measure the cross sections separately for the resolved-photon and direct processes.Comment: 20 pages, Latex format, 4 figures and KEK-mark included. Table 1 revised. To be published in Phys. Lett.
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