9,745 research outputs found

    The T2K Indication of Relatively Large theta_13 and a Natural Perturbation to the Democratic Neutrino Mixing Pattern

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    The T2K Collaboration has recently reported a remarkable indication of the \nu_\mu -> \nu_e oscillation which is consistent with a relatively large value of \theta_{13} in the three-flavor neutrino mixing scheme. We show that it is possible to account for such a result of \theta_{13} by introducing a natural perturbation to the democratic neutrino mixing pattern, without or with CP violation. A testable correlation between \theta_{13} and \theta_{23} is predicted in this ansatz. We also discuss the Wolfenstein-like parametrization of neutrino mixing, and comment on other possibilities of generating sufficiently large \theta_{13} at the electroweak scale.Comment: RevTeX 8 page

    Can the Lepton Flavor Mixing Matrix Be Symmetric?

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    Current neutrino oscillation data indicate that the 3x3 lepton flavor mixing matrix V is likely to be symmetric about its V_{e3}-V_{\mu 2}-V_{\tau 1} axis. This off-diagonal symmetry corresponds to three pairs of {\it congruent} unitarity triangles in the complex plane. Terrestrial matter effects can substantially modify the genuine CP-violating parameter and off-diagonal asymmetries of V in realistic long-baseline experiments of neutrino oscillations.Comment: RexTex 14 pages (4 PS figures). More discussions adde

    Annihilation Type Radiative Decays of BB Meson in Perturbative QCD Approach

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    With the perturbative QCD approach based on kTk_T factorization, we study the pure annihilation type radiative decays B0ϕγB^0 \to \phi\gamma and B0J/ψγB^0\to J/\psi \gamma. We find that the branching ratio of B0ϕγB^0 \to \phi\gamma is (2.70.60.6+0.3+1.2)×1011(2.7^{+0.3+1.2}_{-0.6-0.6})\times10^{-11}, which is too small to be measured in the current BB factories of BaBar and Belle. The branching ratio of B0J/ψγB^0\to J/\psi \gamma is (4.50.50.6+0.6+0.7)×107({4.5^{+0.6+0.7}_{-0.5-0.6}})\times10^{-7}, which is just at the corner of being observable in the BB factories. A larger branching ratio BR(Bs0J/ψγ)5×106BR(B_s^0 \to J/\psi \gamma) \simeq 5 \times 10^{-6} is also predicted. These decay modes will help us testing the standard model and searching for new physics signals.Comment: 4 pages, revtex, with 1 eps figur

    Is the Cabibbo-Kobayashi-Maskawa Matrix Symmetric at the GUT Scale?

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    By use of the one-loop renormalization group equations and current experimental data, we study the off-diagonal asymmetries of the Cabibbo-Kobayashi-Maskawa (CKM) matrix at the GUT scale in the framework of the standard model as well as its two Higgs and supersymmetric extensions. It is concluded that the possibility of a symmetric CKM matrix at the GUT scale has almost been ruled out.Comment: Latex 6 pages plus PS 2 pages. This tiny work would not have been put into this archive if I had not noticed an interesting work by P. Kielanowski et al (hep-ph/9703292), whose conclusion seems to be opposite to mine. (Accepted for publication in J. Phys. G

    More Straightforward Extraction of the Fundamental Lepton Mixing Parameters from Long-Baseline Neutrino Oscillations

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    We point out the simple reversibility between the fundamental neutrino mixing parameters in vacuum and their effective counterparts in matter. The former can therefore be expressed in terms of the latter, allowing more straightforward extraction of the genuine lepton mixing quantities from a variety of long-baseline neutrino oscillation experiments. In addition to the parametrization-independent results, we present the formulas based on the standard parametrization of the lepton flavor mixing matrix and give a typical numerical illustration.Comment: RevTex 10 pages. Minor changes. Phys. Rev. D in printin

    Summary of the NOW'98 Phenomenology Working Group

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    Summary of the Phenomenology Working Group at the Europhysics Neutrino Oscillation Workshop (NOW'98), 7-9 September 1998, Amsterdam.Comment: 66 page

    Testing 3+1 and 3+2 neutrino mass models with cosmology and short baseline experiments

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    Recent results from short--baseline neutrino oscillation experiments and Cosmic Microwave Background anisotropy measurements suggest the presence of additional sterile neutrinos. In this paper we properly combine these data sets to derive bounds on the sterile neutrino masses in the 3+1 and 3+2 frameworks, finding a potentially good agreement between the two datasets. However, when galaxy clustering is included in the analysis a tension between the oscillation and cosmological data is clearly present

    Effects of Chinese materia medica-fuboa danggui jiao on experimental endometriosis

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    The objective of this paper was to investigate the effects of a Chinese Materia Medica variant -Fubao Danggui Jiao (FDJ)-on experimental endometriosis. An endometriosis model was created by virtue of auto-transplantation of endometrial tissue onto rats’ abdominal walls. The implants were allowed to grow for 30 days until the successful completion of the model. After that, forty endometriotic rats were randomly divided into four study groups and given different treatments: (1) negative control group (water, 2ml/kg, per os); (2) FDJ-A group (FDJ, 2ml/kg, per os); (3) FDJ-B group (FDJ, 4ml/kg, per os); (4) Danazol group (70mg/kg, per os). After 30 days with treatments, the volumes of endometriotic implants in each rat were measured. The implants and normal uterine horns were removed for routine histological examination. FDJ caused significant decreases in volumes of the surviving endometriotic implants, with two different doses having statistically equivalent effects. Upon histological examination, FDJ was observed to cause regression of epithelium and stroma of endometriotic implants. FDJ had revealed promising therapeutic effects on endometriosis.Keywords: Fubao Danggui Jiao; Chinese Materia Medica; Endometriosis; Danazol.Non-standard Abbreviations: Fubao Danggui Jiao - FD
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