25,806 research outputs found

    Limits on nu_e and anti-nu_e disappearance from Gallium and reactor experiments

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    The deficit observed in the Gallium radioactive source experiments is interpreted as a possible indication of the disappearance of electron neutrinos. In the effective framework of two-neutrino mixing we obtain sin22ϑ0.03\sin^{2}2\vartheta \gtrsim 0.03 and Δm20.1eV2\Delta{m}^{2} \gtrsim 0.1 \text{eV}^{2}. The compatibility of this result with the data of the Bugey and Chooz reactor short-baseline antineutrino disappearance experiments is studied. It is found that the Bugey data present a hint of neutrino oscillations with 0.02sin22ϑ0.080.02 \lesssim \sin^{2}2\vartheta \lesssim 0.08 and Δm21.8eV2\Delta{m}^{2} \approx 1.8 \text{eV}^{2}, which is compatible with the Gallium allowed region of the mixing parameters. This hint persists in the combined analyses of Bugey and Chooz data, of Gallium and Bugey data, and of Gallium, Bugey, and Chooz data.Comment: 21 pages. Final version to be published in Phys. Rev.

    Extending Hybrid CSP with Probability and Stochasticity

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    Probabilistic and stochastic behavior are omnipresent in computer controlled systems, in particular, so-called safety-critical hybrid systems, because of fundamental properties of nature, uncertain environments, or simplifications to overcome complexity. Tightly intertwining discrete, continuous and stochastic dynamics complicates modelling, analysis and verification of stochastic hybrid systems (SHSs). In the literature, this issue has been extensively investigated, but unfortunately it still remains challenging as no promising general solutions are available yet. In this paper, we give our effort by proposing a general compositional approach for modelling and verification of SHSs. First, we extend Hybrid CSP (HCSP), a very expressive and process algebra-like formal modeling language for hybrid systems, by introducing probability and stochasticity to model SHSs, which is called stochastic HCSP (SHCSP). To this end, ordinary differential equations (ODEs) are generalized by stochastic differential equations (SDEs) and non-deterministic choice is replaced by probabilistic choice. Then, we extend Hybrid Hoare Logic (HHL) to specify and reason about SHCSP processes. We demonstrate our approach by an example from real-world.Comment: The conference version of this paper is accepted by SETTA 201

    Determination of Strong-Interaction Widths and Shifts of Pionic X-Rays with a Crystal Spectrometer

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    Pionic 3d-2p atomic transitions in F, Na, and Mg have been studied using a bent crystal spectrometer. The pionic atoms were formed in the production target placed in the external proton beam of the Space Radiation Effects Laboratory synchrocyclotron. The observed energies and widths of the transitions are E=41679(3) eV and Γ=21(8) eV, E=62434(18) eV and Γ=22(80) eV, E=74389(9) eV and Γ=67(35) eV, in F, Na, and Mg, respectively. The results are compared with calculations based on a pion-nucleus optical potential

    Reachability in Parametric Interval Markov Chains using Constraints

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    Parametric Interval Markov Chains (pIMCs) are a specification formalism that extend Markov Chains (MCs) and Interval Markov Chains (IMCs) by taking into account imprecision in the transition probability values: transitions in pIMCs are labeled with parametric intervals of probabilities. In this work, we study the difference between pIMCs and other Markov Chain abstractions models and investigate the two usual semantics for IMCs: once-and-for-all and at-every-step. In particular, we prove that both semantics agree on the maximal/minimal reachability probabilities of a given IMC. We then investigate solutions to several parameter synthesis problems in the context of pIMCs -- consistency, qualitative reachability and quantitative reachability -- that rely on constraint encodings. Finally, we propose a prototype implementation of our constraint encodings with promising results

    Path integral formulation of Hodge duality on the brane

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    In the warped compactification with a single Randall-Sundrum brane, a puzzling claim has been made that scalar fields can be bound to the brane but their Hodge dual higher-rank anti-symmetric tensors cannot. By explicitly requiring the Hodge duality, a prescription to resolve this puzzle was recently proposed by Duff and Liu. In this note, we implement the Hodge duality via path integral formulation in the presence of the background gravity fields of warped compactifications. It is shown that the prescription of Duff and Liu can be naturally understood within this framework.Comment: 7 pages, LaTe

    PrIC3: Property Directed Reachability for MDPs

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    IC3 has been a leap forward in symbolic model checking. This paper proposes PrIC3 (pronounced pricy-three), a conservative extension of IC3 to symbolic model checking of MDPs. Our main focus is to develop the theory underlying PrIC3. Alongside, we present a first implementation of PrIC3 including the key ingredients from IC3 such as generalization, repushing, and propagation

    Hints of theta_13>0 from global neutrino data analysis

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    Nailing down the unknown neutrino mixing angle theta_13 is one of the most important goals in current lepton physics. In this context, we perform a global analysis of neutrino oscillation data, focusing on theta_13, and including recent results [Neutrino 2008, Proceedings of the XXIII International Conference on Neutrino Physics and Astrophysics, Christchurch, New Zealand, 2008 (unpublished)]. We discuss two converging hints of theta_13>0, each at the level of ~1sigma: an older one coming from atmospheric neutrino data, and a newer one coming from the combination of solar and long-baseline reactor neutrino data. Their combination provides the global estimate sin^2(theta_13) = 0.016 +- 0.010 (1sigma), implying a preference for \theta_13>0 with non-negligible statistical significance (~90% C.L.). We discuss possible refinements of the experimental data analyses, which might sharpen such intriguing indication.Comment: Minor changes in the text. Matches published version in PR

    Research Notes : United States : Genes for resistance to Phytophthora megasperma f. sp. glycinea in PI 273483D, PI 64747, PI 274212, PI 82312N, and PI 340046

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    Several years ago, we identified seven plant introductions resistant to the 16 races of Phytophthora megasperma f. sp. glycinea Kuan and Erwin (Pmg) known at that time. Each of these was crossed to the eight cultivars in Table 1 to determine how resistance was controlled. They were not crossed to cultivars that contained Rps2 or Rps5 because Rps2 was found using root inoculation in a liquid culture solution, and Rps5 was described after this study was started

    Restricted random walk model as a new testing ground for the applicability of q-statistics

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    We present exact results obtained from Master Equations for the probability function P(y,T) of sums y=t=1Txty=\sum_{t=1}^T x_t of the positions x_t of a discrete random walker restricted to the set of integers between -L and L. We study the asymptotic properties for large values of L and T. For a set of position dependent transition probabilities the functional form of P(y,T) is with very high precision represented by q-Gaussians when T assumes a certain value TL2T^*\propto L^2. The domain of y values for which the q-Gaussian apply diverges with L. The fit to a q-Gaussian remains of very high quality even when the exponent aa of the transition probability g(x)=|x/L|^a+p with 0<p<<1 is different from 1, all though weak, but essential, deviation from the q-Gaussian does occur for a1a\neq1. To assess the role of correlations we compare the T dependence of P(y,T) for the restricted random walker case with the equivalent dependence for a sum y of uncorrelated variables x each distributed according to 1/g(x).Comment: 5 pages, 7 figs, EPL (2011), in pres
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