7,856 research outputs found

    Neutrino Mixings in SO(10) with Type II Seesaw and theta_{13}

    Full text link
    We analyze a class of supersymmetric SO(10) grand unified theories with type II seesaw for neutrino masses, where the contribution to PMNS matrix from the neutrino sector has an exact tri-bi-maximal (TBM) form, dictated by a broken S_4 symmetry. The Higgs fields that determine the fermion masses are two 10 fields and one 126 field, with the latter simultaneously contributing to neutrino as well as charged fermion masses. Fitting charged fermion masses and the CKM mixings lead to corrections to the TBM mixing that determine the final PMNS matrix with the predictions theta_{13} ~ 4-6 degrees and the Dirac CP phase to be between -10 and +15 degrees. We also show correlations between various mixing angles which can be used to test the model.Comment: 16 pages, 4 figures, 2 tables; typos corrected in Eq. (4) and Table I

    Leptogenesis with TeV Scale Inverse Seesaw in SO(10)

    Full text link
    We discuss leptogenesis within a TeV-scale inverse seesaw model for neutrino masses where the seesaw structure is guaranteed by an SO(10) symmetry. Contrary to the TeV-scale type-I gauged seesaw, the constraints imposed by successful leptogenesis in these models are rather weak and allow for the extra gauge bosons W_R and Z' to be in the LHC accessible range. The key differences in the inverse seesaw compared to the type I case are: (i) decay and inverse decay rates larger than the scatterings involving extra gauge bosons due to the large Yukawa couplings and (ii) the suppression of the washout due to very small lepton number breaking.Comment: References and a few comments added, improved figures; version to be published in PR

    Natural TeV-Scale Left-Right Seesaw for Neutrinos and Experimental Tests

    Full text link
    We present a TeV-scale left-right ultraviolet completion of type-I seesaw for neutrino masses based on the SU(2)L×SU(2)R×U(1)BLSU(2)_L\times SU(2)_R\times U(1)_{B-L} gauge group without parity, which leads to "large" light-heavy neutrino mixing while keeping the neutrino masses small in a natural manner guaranteed by discrete symmetries. We point out specific observable implications of this class of models if the SU(2)RSU(2)_R-breaking scale is of order 5 TeV, in searches for lepton flavor violating processes such as μeγ\mu\to e\gamma, μ3e\mu\to 3 e and μe\mu-e conversion in nuclei, and lepton number violating processes such as neutrinoless double beta decay as well as at the LHC. In particular, if the upper limit on BR(μeγ)(\mu\to e\gamma) improves by one order of magnitude, a large range of the parameters of the model would be ruled out.Comment: 34 pages, 8 figures, 10 tables; some comments and references added; version accepted for publication in Phys. Rev.

    A Scalable Tile Map Service for Distributing Dynamic Choropleth Maps

    Get PDF
    In this paper we propose a solution to several key limitations of current web based mapping systems: slow rendering speeds and the restriction of online map viewing to a small number of areal units as well as a limited number of users. Our approach is implemented as a Scalable Tile Map Service that distributes dynamic choropleth maps in real-time through a new caching methodology. This new Map Service lays the foundation for advances in web based applications reliant on dynamic map rendering such as emergency management systems and interactive exploratory spatial data analysis. We present the results of an empirical illustration in which this new methodology is used to facilitate collaborative decision making by visualizing spatial outcomes of simulation results on the fly.

    Dark Energy and the Statistical Study of the Observed Image Separations of the Multiply Imaged Systems in the CLASS Statistical Sample

    Full text link
    The present day observations favour a universe which is flat, accelerated and composed of 1/3\sim 1/3 matter (baryonic + dark) and 2/3\sim 2/3 of a negative pressure component, usually referred to as dark energy or quintessence. The Cosmic Lens All Sky Survey (CLASS), the largest radio-selected galactic mass scale gravitational lens search project to date, has resulted in the largest sample suitable for statistical analyses. In the work presented here, we exploit observed image separations of the multiply imaged lensed radio sources in the sample. We use two different tests: (1) image separation distribution function n(Δθ)n(\Delta\theta) of the lensed radio sources and (2) {\dtheta}_{\mathrm{pred}} vs {\dtheta}_{\mathrm{obs}} as observational tools to constrain the cosmological parameters ww and \Om. The results are in concordance with the bounds imposed by other cosmological tests.Comment: 20 pages latex; Modified " Results and Discussion " section, new references adde
    corecore