5,403 research outputs found

    Observation of the anisotropy in arrival direction of Cosmic Rays with IceCube

    Full text link
    The IceCube Neutrino Observatory is a kilometer-scale detector currently under construction at the South Pole. In its final configuration the detector will comprise 5160 Digital Optical Modules (DOMs) deployed on 86 strings between 1.5-2.5 km deep within the ice. While still incomplete, the detector has already recorded tens of billions of cosmic ray muons with a median energy of 20 TeV. This large sample has been used to study the arrival direction distribution of the cosmic rays. We report the observation of an anisotropy in the cosmic rays arrival direction at two different angular scales. The observed large scale anisotropy seems to be a continuation of similar structures observed in the Northern Sky by several experiments. IceCube observes also significant features on the angular scale of 203020^{\circ} - 30^{\circ} that might be part of the larger scale structure

    THE IMPACT OF CHILEAN FRUIT SECTOR DEVELOPMENT ON FEMALE EMPLOYMENT AND HOUSEHOLD INCOME

    Get PDF
    Modern fruit sector development in Chile led to agricultural employment for women, though usually only as temporary workers and often at a piece rate. Nonetheless, fruit sector employment offered women access to income and personal fulfillment previously lacking. This paper links the fruit sector to improving female and family economic welfare in rural Chile and changing gender relations. Using a unique longitudinal data set, we examine women's decisions regarding labor force participation and employment, their earnings and contributions to household income, and their attitudes toward employment to understand how new opportunities are changing women, their households, and the rural sector.Consumer/Household Economics, Labor and Human Capital,

    A Family of Continuous Variable Entanglement Criteria using General Entropy Functions

    Full text link
    We derive a family of entanglement criteria for continuous variable systems based on the R\'enyi entropy of complementary distributions. We show that these entanglement witnesses can be more sensitive than those based on second-order moments, as well as previous tests involving the Shannon entropy [Phys. Rev. Lett. \textbf{103}, 160505 (2009)]. We extend our results to include the case of discrete sampling, and develop another set of entanglement tests using the discrete Tsallis entropy. We provide several numerical results which show that our criteria can be used to identify entanglement in a number of experimentally relevant quantum states.Comment: 8 pages, 3 figure

    Gauge invariant electromagnetic properties of fermions induced by CPT violation in the Standard Model Extension

    Full text link
    Low-energy Lorentz-invariant quantities could receive contributions from a fundamental theory producing small Lorentz-violating effects. Within the Lorentz-violating extension of quantum electrodynamics, we investigate, perturbatively, the contributions to the one-loop ffγff\gamma vertex from the CPTCPT-violating axial coupling of a vector background field to fermions. We find that the resulting vertex function has a larger set of Lorentz structures than the one characterizing the usual, Lorentz invariant, parametrization of the ffγff\gamma vertex. We prove gauge invariance of the resulting one-loop expression through a set of gauge invariant nonrenormalizable operators introducing new-physics effects at the first and second orders in Lorentz violation, and which generate tree-level contributions to the ffγff\gamma vertex. Whereas loop contributions involving parameters that violate Lorentz invariance at the first order are CPTCPT-odd, those arising at the second order are CPTCPT-even, so that contributions to low-energy physics are restricted to emerge for the first time at the second order. In this context, we derive a contribution to anomalous magnetic moment of fermions, which we use to set a bound on Lorentz violation.Comment: 13 pages, 1 figure, 1 table, a couple of references were adde

    Reliable Entanglement Detection Under Coarse--Grained Measurements

    Full text link
    We derive reliable entanglement witnesses for coarse--grained measurements on continuous variable systems. These witnesses never return a "false positive" for identification of entanglement, under any degree of coarse graining. We show that, even in the case of Gaussian states, entanglement witnesses based on the Shannon entropy can outperform those based on variances. We apply our results to experimental identification of spatial entanglement of photon pairs.Comment: Dedicated to Iwo Bialynicki-Birula on his 80th birthday, who inspired much of this wor

    Bounding the ZtcZ^\prime tc coupling from D0D0ˉD^{0}-\bar{D^{0}} mixing and single top production at the ILC

    Full text link
    In the present work the ZtcZ^\prime tc coupling is bounded by using the current experimental data on the D0D0ˉD^{0}-\bar{D^{0}} meson-mixing system. It is found that the strength associated to this coupling is less than 5.75×1025.75\times 10^{-2}. The single top production through the e+eZtce^+e^-\to Z^\prime\to tc process at the ZZ^\prime boson resonance is studied and we found that around 10710^7 tctc events will be expected at the International Linear Collider. For the ZtcZ^\prime\to tc decay, we predict a branching ratio of 10210^{-2}.Comment: Revised version. Now, 11 pages and 6 figure

    Z'tc coupling from D0-D0 mixing

    Full text link
    We bound the ZtcZ^\prime tc coupling using the D0D0ˉD^{0}-\bar{D^{0}} meson mixing system. We obtained such coupling which is less than 5.75×1025.75\times 10^{-2}. We have studied the ZZ^\prime boson resonance considering single top production in the e+eZtce^+e^-\to Z^\prime\to tc process. We obtained the number of events which is expected to be less than 10710^7 at the International Linear Collider scenario. We get a branching ratio of the order of 10210^{-2} for the ZtcZ^\prime\to tc decay.Comment: 4 pages, 5 figure
    corecore