234 research outputs found

    Study of Extra Space Dimensions in Vector Boson Pair Production at LEP

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    Recent theoretical scenarios propose that quantum gravity effects may manifest at LEP energies by means of gravitons that couple to Standard Model particles and propagate into extra space dimensions. These predictions are checked against the most recent experimental results on photon, W and Z pair production. No deviations from the Standard Model expectations are found and limits of the order of 1 TeV on the scale of these models are set.Comment: 6 pages, 1 figur

    Determining highway corridors

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    In the highway development process, the first planning stage is that of selecting a corridor along which the highway is to pass. Highway corridor selection represents a multicriteria decision process in which a variety of social, enviromental and economic factors must be evaluated and weighted for a large number of corridor alternatives. This paper proposes a demand-based approach to provide a set of potential corridors. The problem is formulated as a continuous location model which seeks a set of optimal corridors with respect to the demand of potential users while satisfying budget constraints. This model uses geographical information in order to estimate the length-dependent costs (such as pavement and construction cost) and the cost of earth movement. A procedure for finding the best local minima of the optimization model is proposed. This method is tested using the Particle Swarm Optimization algorithm, two algorithms of the Simulated Annealing type and the Simplex Nedelmar method. An application using the Castilla-La Mancha\s geographic database is presented

    Primordial non-Gaussianity with Angular correlation function: Integral constraint and validation for DES

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    Local primordial non-Gaussianity (PNG) is a promising observable of the underlying physics of inflation, characterised by fNLlocf_{\rm NL}^{\rm loc}. We present the methodology to measure fNLlocf_{\rm NL}^{\rm loc} from the Dark Energy Survey (DES) data using the 2-point angular correlation function (ACF) with scale-dependent bias. One of the focuses of the work is the integral constraint. This condition appears when estimating the mean number density of galaxies from the data and is key in obtaining unbiased fNLlocf_{\rm NL}^{\rm loc} constraints. The methods are analysed for two types of simulations: ∼246\sim 246 GOLIAT-PNG N-body small area simulations with fNLf_{\rm NL} equal to -100 and 100, and 1952 Gaussian ICE-COLA mocks with fNL=0f_{\rm NL}=0 that follow the DES angular and redshift distribution. We use the ensemble of GOLIAT-PNG mocks to show the importance of the integral constraint when measuring PNG, where we recover the fiducial values of fNLf_{\rm NL} within the 1σ1\sigma when including the integral constraint. In contrast, we found a bias of ΔfNL∼100\Delta f_{\rm NL}\sim 100 when not including it. For a DES-like scenario, we forecast a bias of ΔfNL∼23\Delta f_{\rm NL} \sim 23, equivalent to 1.8σ1.8\sigma, when not using the IC for a fiducial value of fNL=100f_{\rm NL}=100. We use the ICE-COLA mocks to validate our analysis in a realistic DES-like setup finding it robust to different analysis choices: best-fit estimator, the effect of IC, BAO damping, covariance, and scale choices. We forecast a measurement of fNLf_{\rm NL} within σ(fNL)=31\sigma(f_{\rm NL})=31 when using the DES-Y3 BAO sample, with the ACF in the 1 deg<θ<20 deg1\ {\rm deg}<\theta<20\ {\rm deg} range.Comment: Version after MNRAS reviewer comments. Improved discussion in Section 7. 16 pages, 11 figure
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