24,444 research outputs found

    Generalised CP and Δ(96)\Delta (96) Family Symmetry

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    We perform a comprehensive study of the Δ(96)\Delta (96) family symmetry combined with the generalised CP symmetry HCPH_{\rm{CP}}. We investigate the lepton mixing parameters which can be obtained from the original symmetry Δ(96)⋊HCP\Delta (96)\rtimes H_{\rm{CP}} breaking to different remnant symmetries in the neutrino and charged lepton sectors, namely GνG_{\nu} and GlG_l subgroups in the neutrino and the charged lepton sector respectively, and the remnant CP symmetries from the breaking of HCPH_{\rm{CP}} are HCPνH^{\nu}_{\rm{CP}} and HCPlH^{l}_{\rm{CP}}, respectively, where all cases correspond to a preserved symmetry smaller than the full Klein symmetry, as in the semi-direct approach, leading to predictions which depend on a single undetermined real parameter, which may be fitted to the reactor angle for example. We discuss 26 possible cases, including a global χ2\chi^2 determination of the best fit parameters and the correlations between mixing parameters, in each case.Comment: 71 pages, 10 figure

    Physico-chemical factors and bacteria in fish ponds

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    Analyses of pond water and mud samples show that nitrifying bacteria (including ammonifying bacteria, nitrite bacteria, nitrobacteria and denitrifying bacteria) are in general closely correlated with various physico-chemical factors, ammonifying bacteria are mainly correlated with dissolved oxygen; denitrifying bacteria are inversely correlated with phosphorus; nitrite bacteria are closely correlated with nitrites, nitrobacteria are inversely correlated with ammoniac nitrogen. The nitrifying bacteria are more closely correlated with heterotrophic bacteria. Nitrobacteria are inversely correlated with anaerobic heterotrophic bacteria. The correlation is quite weak between all the nitrite bacteria which indicates that the nitrite bacteria have a controlling and regulating function in water quality and there is no interdependence as each plays a role of its own. The paper also discusses how the superficial soil (pond mud down to 3.5 cm deep) and different layers of the mud affect the biomass of bacteria. The study shows that the top superficial layer (down to 1.5 cm deep) is the major area for decomposing and converting organic matter

    The KKˉπK \bar K \pi decay of the f1(1285)f_1(1285) and its nature as a K∗Kˉ−ccK^* \bar K -cc molecule

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    We investigate the decay of f1(1285)→πKKˉf_1(1285) \to \pi K \bar K with the assumption that the f1(1285)f_1(1285) is dynamically generated from the K∗Kˉ−ccK^* \bar{K} - cc interaction. In addition to the tree level diagrams that proceed via f1(1285)→K∗Kˉ−cc→πKKˉf_1(1285) \to K^* \bar{K} - cc \to \pi K \bar K, we take into account also the final state interactions of KKˉ→KKˉK \bar K \to K \bar K and πK→πK\pi K \to \pi K. The partial decay width and mass distributions of f1(1285)→πKKˉf_1(1285) \to \pi K \bar K are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the mass distributions. The predicted mass distributions are significantly different from phase space and tied to the K∗Kˉ−ccK^* \bar{K} - cc nature of the f1(1285)f_1(1285) state.Comment: Published versio

    Two ultracold atoms in a completely anisotropic trap

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    As a limiting case of ultracold atoms trapped in deep optical lattices, we consider two interacting atoms trapped in a general anisotropic harmonic oscillator potential, and obtain exact solutions of the Schrodinger equation for this system. The energy spectra for different geometries of the trapping potential are compared.Comment: 4 pages, 2 figure

    Leptogenesis and residual CP symmetry

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    We discuss flavour dependent leptogenesis in the framework of lepton flavour models based on discrete flavour and CP symmetries applied to the type-I seesaw model. Working in the flavour basis, we analyse the case of two general residual CP symmetries in the neutrino sector, which corresponds to all possible semi-direct models based on a preserved Z2Z_2 in the neutrino sector, together with a CP symmetry, which constrains the PMNS matrix up to a single free parameter which may be fixed by the reactor angle. We systematically study and classify this case for all possible residual CP symmetries, and show that the RR-matrix is tightly constrained up to a single free parameter, with only certain forms being consistent with successful leptogenesis, leading to possible connections between leptogenesis and PMNS parameters. The formalism is completely general in the sense that the two residual CP symmetries could result from any high energy discrete flavour theory which respects any CP symmetry. As a simple example, we apply the formalism to a high energy S4S_4 flavour symmetry with a generalized CP symmetry, broken to two residual CP symmetries in the neutrino sector, recovering familiar results for PMNS predictions, together with new results for flavour dependent leptogenesis.Comment: 35 pages, 8 figure

    A loop group method for minimal surfaces in the three-dimensional Heisenberg group

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    We characterize constant mean curvature surfaces in the three-dimensional Heisenberg group by a family of flat connections on the trivial bundle \D \times \GL over a simply connected domain D\mathbb{D} in the complex plane. In particular for minimal surfaces, we give an immersion formula, the so-called Sym-formula, and a generalized Weierstrass type representation via the loop group method.Comment: 40 pages, v2: The argument for branch points has been fixed and the references have been updated. v3: The argument for canonical examples has been fixed and the classification for homogeneous surfaces has been added v4: Some typos are fixed and Remark 5.4 (3) is adde
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