794 research outputs found

    Analysis of a model with a common source of CP violation

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    We work in a model where all CP violating phenomena have a common source. CP is spontaneously broken at a large scale VV through the phase of a complex singlet scalar. An additional SU(2)LSU(2)_L singlet vector-like down-type quark relates this high scale CP violation to low energy. We quantitatively analyze this model in the quark sector. We obtain the numerical values of the parameters of the Lagrangian in the quark sector for a specific ansatz of the 4×44\times4 down-type quark mass matrix where the weak phase is generated minimally. ZbˉbZ \bar b b vertex will modify in presence of the extra vector-like down-type quark. From the experimental lower bound of the partial decay width ZbˉbZ\to \bar b b we find out the lower bound of the additional down-type quark mass. Tree level flavor changing neutral current appears in this model due to the presence of the extra vector-like down-type quark. We give the range of values of the mass splitting ΔmBq\Delta m_{B_q} in Bq0Bˉq0B^0_q-{\bar B}^0_q system using SM box, ZZ mediating tree level and ZZ mediating one loop diagrams together for both q=d,sq=d, s. We find out the analytical expression for Γ12q\Gamma_{12}^q in this model from standard box, ZZ and Higgs mediated penguin diagrams for Bq0Bˉq0B^0_q-{\bar B}^0_q system, q=d,sq=d,s. From this we numerically evaluate the decay width difference ΔΓBq/ΓBq|\Delta\Gamma_{B_q}/\Gamma_{B_q}|. We also find out the numerical values of the CP asymmetry parameters aJa_J and aπa_\pi for the decays Bd0J/ψKsB^0_d\to J/\psi K_s and Bd0π+πB^0_d\to \pi^+ \pi^- respectively. We get the lower bound of the scale VV through the upper bound of the strong CP phase.Comment: 20 pages, no figures New materials and references have been added. Text has been modified. To be appear in J.Phys.

    Neutrino masses, cosmological bound and four zero Yukawa textures

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    Four zero neutrino Yukawa textures in a specified weak basis, combined with μτ\mu\tau symmetry and type-I seesaw, yield a highly constrained and predictive scheme. Two alternately viable 3×33\times3 light neutrino Majorana mass matrices mνA/mνBm_{\nu A}/m_{\nu B} result with inverted/normal mass ordering. Neutrino masses, Majorana in character and predicted within definite ranges with laboratory and cosmological inputs, will have their sum probed cosmologically. The rate for 0νββ0\nu\beta\beta decay, though generally below the reach of planned experiments, could approach it in some parameter region. Departure from μτ\mu\tau symmetry due to RG evolution from a high scale and consequent CP violation, with a Jarlskog invariant whose magnitude could almost reach 6×1036\times 10^{-3}, are explored.Comment: Published versio

    TiO2 coated MWCNT decorated by Fe3O4 nanoparticle as electrode material for Supercapacitor Application

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    TiO2 coated multi wall carbon nanotube (TiCN) and Fe3O4 based electrode material for the application in electro chemical devices has been produced through a simple approach. Morphological and electro chemical properties of the prepared nanocomposites were determined through field emission scanning electron microscopy (FESEM) and cyclic voltammetry (CV) and impedance analysis, respectively. Sol-gel technique was hired to synthesize TiCN and in-situ chemical co-precipitation technique was used for the formation of magnetite particles (Fe3O4) on the surface of acid-modified multiwall carbon nanotube (MWCNT). Maximum specific capacitance obtained from CV is 221 F/g

    Water poverty in the northeastern hill region (India): potential alleviation through multiple-use water systems: cross-learnings from Nepal Hills

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    Water poverty index / Construction / Multiple use / Water storage / Farming systems / Villages / Social aspects / Drip irrigation / India / Nepal / Nagaland / Mon district / Lampong Sheanghah

    Scaling ansatz, four zero Yukawa textures and large θ13\theta_{13}

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    We investigate 'Scaling ansatz' in the neutrino sector within the framework of type I seesaw mechanism with diagonal charged lepton and right handed Majorana neutrino mass matrices (MRM_R). We also assume four zero texture of Dirac neutrino mass matrices (mDm_D) which severely constrain the phenomenological outcomes of such scheme. Scaling ansatz and the present neutrino data allow only Six such matrices out of 126 four zero Yukawa matrices. In this scheme, in order to generate large θ13\theta_{13} we break scaling ansatz in mDm_D through a perturbation parameter and we also show our breaking scheme is radiatively stable. We further investigate CP violation and baryogenesis via leptogenesis in those surviving textures.Comment: 25 pages, 8 figures, Accepted for publication in Phys. Rev.

    Quenching of nucleotide-derived radicals by bisbenzimidazole derivative Hoechst-33258 in aqueous solution

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    The pulse radiolysis technique has been employed to investigate the reaction of DNA-minor-groove ligand bisbenzimidazole Hoechst 33258 with pyrimidine and purine nucleotide-derived radicals. Formation of an N-centred Hoechst-33258 radical is observed. Bimolecular rate constants and the yields of Hoechst-33258 radical have been evaluated. While the rate constant for the reaction of pyrimidine-derived radicals with Hoechst-33258 remained the same (1-2) × 109 dm3 mol-1 s-1, the yields of the Hoechst-33258 radical varied from 25% (5'-cytidine monophosphate) to 75% (5'-guanosine monophosphate) under anoxic conditions. The rate constant values for the reaction of purine-derived radicals with Hoechst-33258, under oxic and anoxic conditions, remained the same whereas with pyrimidine-derived radicals, the rate constant value under oxic conditions was about two orders of magnitude lower than under anoxic conditions. The difference in the yields of Hoechst-33258 radical with various nucleotide-derived radicals suggest the formation of different types of radicals and that the reaction mainly occurs by electron transfer from Hoechst-33258 to the nucleotide radicals

    Predictions of Neutrino Mixing Angles in a T'Model

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    Flavor symmetry (T×Z2T^{'} \times Z_2) where TT^{'} is the binary tetrahedral group predicts for neutrino mixing angles θ13=2(π4θ23)\theta_{13} = \sqrt{2} (\frac{\pi}{4} - \theta_{23}) and, with one phenomenological input, provides upper and lower bounds on both θ13\theta_{13} and θ23\theta_{23}. The predictions arise from the deviation of the Cabibbo angle Θ12\Theta_{12} from its lowest-order value tan2Θ12=(2)/3\tan 2\Theta_{12} = (\sqrt{2})/3 and from the TT^{'} mechanism which relates mixing of (ντ,νμ,νe)(\nu_{\tau}, \nu_{\mu}, \nu_e) neutrinos to mixing of (s,d)(s, d) quarks.Comment: Typos. Reference adde

    TT^{'} Predictions of PMNS and CKM Angles

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    Generalizing a previous model to accommodate the third quark family and CP violation, we present a TT^{'} model which predicts tribimaximal neutrino (PMNS) mixings while the central predictions for quark mixings are Vtd/Vts=0.245|V_{td}/V_{ts}| = 0.245 and Vub/Vcb=0.237|V_{ub}/V_{cb}| = 0.237 with a predicted CP violating KM phase δKM=65.80\delta_{KM} = 65.8^{0}. All these are acceptably close to experiment, including the KM phase for which the allowed values are 630<δKM<72063^{0} < \delta_{KM} < 72^{0}, and depend only on use of symmetry T×Z2T^{'} \times Z_2 to define the model and no additional parameters.Comment: Simplified presentatio
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