1,595 research outputs found

    Constraining new physics scenarios in neutrino oscillations from Daya Bay data

    Full text link
    We perform for the first time a detailed fit to the νˉeνˉe\bar \nu_e \to \bar \nu_e disappearance data of the Daya Bay experiment to constrain the parameter space of models where sterile neutrinos can propagate in a large compactified extra dimension (LED) and models where non-standard interactions affect the neutrino production and detection (NSI). We find that the compactification radius RR in LED scenarios can be constrained at the level of 0.57μm0.57 \, \mu m for normal ordering and of 0.19μm0.19\, \mu m for inverted ordering, at 2σ\sigma confidence level. For the NSI model, reactor data put a strong upper bound on the parameter εee\varepsilon_{ee} at the level of 103\sim 10^{-3}, whereas the main effect of εeμ\varepsilon_{e\mu} and εeτ\varepsilon_{e\tau} is a worsening of the determination of θ13\theta_{13}.Comment: 5 pages, 2 figure

    Response to a rabies epidemic in Bali, Indonesia

    Get PDF
    Emergency vaccinations and culling failed to contain an outbreak of rabies in Bali, Indonesia, during 2008–2009. Subsequent island-wide mass vaccination (reaching 70% coverage, >200,000 dogs) led to substantial declines in rabies incidence and spread. However, the incidence of dog bites remains high, and repeat campaigns are necessary to eliminate rabies in Bali

    Probing new physics scenarios in accelerator and reactor neutrino experiments

    Full text link
    We perform a detailed combined fit to the νeνe\overline \nu_e \rightarrow \overline \nu_e disappearence data of the Daya Bay experiment and the appearance νμνe\nu_{\mu} \rightarrow \nu_{e} and disappearance νμνμ\nu_{\mu} \rightarrow \nu_{\mu} data of the Tokai to Kamioka (T2K) one in the presence of two models of new physics affecting neutrino oscillations, namely a model where sterile neutrinos can propagate in a large compactified extra dimension and a model where non-standard interactions (NSI) affect the neutrino production and detection. We find that the Daya Bay \oplus T2K data combination constrains the largest radius of the compactified extra dimensions to be R0.17R\lesssim 0.17 μm\mu {\rm m} at 2σ\sigma C.L. (for the inverted ordering of the neutrino mass spectrum) and the relevant NSI parameters in the range O(103)O(102){\mathcal O}(10^{-3})-{\mathcal O}(10^{-2}), for particular choices of the charged parity violating phases.Comment: 18 pages, 10 figures, 4 tables; typos corrected; matches published versio

    Automated search for galactic star clusters in large multiband surveys: I. Discovery of 15 new open clusters in the Galactic anticenter region

    Get PDF
    Aims: According to some estimations, there are as many as 100000 open clusters in the Galaxy, but less than 2000 of them have been discovered, measured, and cataloged. We plan to undertake data mining of multiwavelength surveys to find new star clusters. Methods: We have developed a new method to search automatically for star clusters in very large stellar catalogs, which is based on convolution with density functions. We have applied this method to a subset of the Two Micron All Sky Survey catalog toward the Galactic anticenter. We also developed a method to verify whether detected stellar groups are real star clusters, which tests whether the stars that form the spatial density peak also fall onto a single isochrone in the color-magnitude diagram. By fitting an isochrone to the data, we estimate at the same time the main physical parameters of a cluster: age, distance, color excess. Results: For the present paper, we carried out a detailed analysis of 88 overdensity peaks detected in a field of 16×1616\times16 degrees near the Galactic anticenter. From this analysis, 15 overdensities were confirmed to be new open clusters and the physical and structural parameters were determined for 12 of them; 10 of them were previously suspected to be open clusters by Kronberger (2006) and Froebrich (2007). The properties were also determined for 13 yet-unstudied known open clusters, thus almost tripling the sample of open clusters with studied parameters in the anticenter. The parameters determined with this method showed a good agreement with published data for a set of well-known clusters.Comment: accepted to A&

    Rotation of the cluster of galaxies A2107

    Full text link
    We present indications of rotation in the galaxy cluster A2107 by a method that searches for the maximum gradient in the velocity field in a flat disk-like model of a cluster. Galaxies from cumulative sub-samples containing more and more distant members from the cluster centre, are projected onto an axis passing through the centre and we apply a linear regression model on the projected distances xx and the line-of-sight velocities VV. The axis with the maximum linear correlation coefficient rmax=max[r(V,x)]r_{max} = \max [ r(V,x) ] defines the direction of the maximum velocity gradient, and consequently it presents the major axis of the apparently elliptical cluster. Because the effects of rotation are subtle, we put strong emphasis on the estimation of the uncertainties of the results by implementing different bootstrap techniques. We have found the rotational effects are more strongly expressed from distances 0.26÷0.540.26 \div 0.54 Mpc from the cluster centre. The total virial mass of the cluster is (3.2\pm0.6)\times10^{14} {\cal M}_{\sun}, while the virial mass, corrected for the rotation, is (2.8\pm0.5) \times 10^{14}{\cal M}_{\sun}.Comment: 7 pages, 9 figures gzipped tar file. to be published in MNRA

    Lie Superalgebras and the Multiplet Structure of the Genetic Code II: Branching Schemes

    Full text link
    Continuing our attempt to explain the degeneracy of the genetic code using basic classical Lie superalgebras, we present the branching schemes for the typical codon representations (typical 64-dimensional irreducible representations) of basic classical Lie superalgebras and find three schemes that do reproduce the degeneracies of the standard code, based on the orthosymplectic algebra osp(5|2) and differing only in details of the symmetry breaking pattern during the last step.Comment: 34 pages, 9 tables, LaTe

    A Two-Form Formulation of the Vector-Tensor Multiplet in Central Charge Superspace

    Get PDF
    A two-form formulation for the N=2 vector-tensor multiplet is constructed using superfield methods in central charge superspace. The N=2 non-Abelian standard supergauge multiplet in central charge superspace is also discussed, as is with the associated Chern-Simons form. We give the constraints, solve the Bianchi identities and present the action for a theory of the vector-tensor multiplet coupled to the non-Abelian supergauge multiplet via the Chern-Simons form.Comment: 16 pages, LaTeX2e with AMS-LaTe

    Galactic Archaeology with CoRoT and APOGEE: Creating mock observations from a chemodynamical model

    Get PDF
    In a companion paper, we have presented the combined asteroseismic-spectroscopic dataset obtained from CoRoT lightcurves and APOGEE infra-red spectra for 678 solar-like oscillating red giants in two fields of the Galactic disc (CoRoGEE). We have measured chemical abundance patterns, distances, and ages of these field stars which are spread over a large radial range of the Milky Way's disc. Here we show how to simulate this dataset using a chemodynamical Galaxy model. We also demonstrate how the observation procedure influences the accuracy of our estimated ages.Comment: 5 pages, 6 figures. To appear in Astronomische Nachrichten, special issue "Reconstruction the Milky Way's History: Spectroscopic surveys, Asteroseismology and Chemo-dynamical models", Guest Editors C. Chiappini, J. Montalb\'an, and M. Steffe

    Evolution and Nucleosynthesis of AGB stars in Three Magellanic Cloud Clusters

    Full text link
    We present stellar evolutionary sequences for asymptotic giant branch (AGB) stars in the Magellanic Cloud clusters NGC 1978, NGC 1846 and NGC 419. The new stellar models for the three clusters match the observed effective temperatures on the giant branches, the oxygen-rich to carbon-rich transition luminosities, and the AGB-tip luminosities. A major finding is that a large amount of convective overshoot (up to 3 pressure scale heights) is required at the base of the convective envelope during third dredge-up in order to get the correct oxygen-rich to carbon-rich transition luminosity. The stellar evolution sequences are used as input for detailed nucleosynthesis calculations. For NGC 1978 and NGC 1846 we compare our model results to the observationally derived abundances of carbon and oxygen. We find that additional mixing processes (extra-mixing) are required to explain the observed abundance patterns. For NGC 1846 we conclude that non-convective extra-mixing processes are required on both the RGB and the AGB, in agreement with previous studies. For NGC 1978 it is possible to explain the C/O and 12C/13C abundances of both the O-rich and the C-rich AGB stars by assuming that the material in the intershell region contains high abundances of both C and O. This may occur during a thermal pulse when convective overshoot at the inner edge of the flash-driven convective pocket dredges C and O from the core to the intershell. For NGC 419 we provide our predicted model abundance values although there are currently no published observed abundance studies for the AGB stars in this cluster.Comment: 16 figures, 3 tables, Accepted for publication in Ap
    corecore