713 research outputs found

    CERN n_TOF facility: Performance report

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    An innovative neutron Time-of-Flight facility (n_TOF) has recently become operative at CERN. The high neutron flux is obtained by the spallation of 20 GeV/c protons onto a solid lead target. The proton beam is delivered by the Proton Synchrotron (PS) at CERN capable of providing up to four sharp bunches (RMS 6 ns) with an intensity of 7x10^12 protons per bunch within a 14.4s supercycle. The present report describes the outstanding characteristics of this facility: high neutron flux of 10^6 n/cm^2/7x10^12 p at 185 m, wide spectral function from 1 eV up to 250 MeV, low repetition rates, an excellent energy resolution of 2x10^-4 in the resonance region and low background conditions. These unique features open new possibilities for high precision neutron induced cross section measurements relevant to Nuclear Technology, Nuclear Astrophysics and fundamental Nuclear Physics

    T violation and the unidirectionality of time

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    An increasing number of experiments at the Belle, BNL, CERN, DA{\Phi}NE and SLAC accelerators are confirming the violation of time reversal invariance (T). The violation signifies a fundamental asymmetry between the past and future and calls for a major shift in the way we think about time. Here we show that processes which violate T symmetry induce destructive interference between different paths that the universe can take through time. The interference eliminates all paths except for two that represent continuously forwards and continuously backwards time evolution. Evidence from the accelerator experiments indicates which path the universe is effectively following. This work may provide fresh insight into the long-standing problem of modeling the dynamics of T violation processes. It suggests that T violation has previously unknown, large-scale physical effects and that these effects underlie the origin of the unidirectionality of time. It may have implications for the Wheeler-DeWitt equation of canonical quantum gravity. Finally it provides a view of the quantum nature of time itself.Comment: 24 pages, 5 figures. Final version accepted for publishing in Foundations of Physics. The final publication is available at http://www.springerlink.com/content/y3h4174jw2w78322

    Mechanics: non-classical, non-quantum

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    A non-classical, non-quantum theory, or NCQ, is any fully consistent theory that differs fundamentally from both the corresponding classical and quantum theories, while exhibiting certain features common to both. Such theories are of interest for two primary reasons. Firstly, NCQs arise prominently in semi-classical approximation schemes. Their formal study may yield improved approximation techniques in the near-classical regime. More importantly for the purposes of this note, it may be possible for NCQs to reproduce quantum results over experimentally tested regimes while having a well defined classical limit, and hence are viable alternative theories. We illustrate an NCQ by considering an explicit class of NCQ mechanics. Here this class will be arrived at via a natural generalization of classical mechanics formulated in terms of a probability density functional

    Strong rescattering in K-> 3pi decays and low-energy meson dynamics

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    We present a consistent analysis of final state interactions in K→3π{K\rightarrow 3\pi} decays in the framework of Chiral Perturbation Theory. The result is that the kinematical dependence of the rescattering phases cannot be neglected. The possibility of extracting the phase shifts from future KS−KLK_S-K_L interference experiments is also analyzed.Comment: 14 pages in RevTex, 3 figures in postscrip

    Tourism income and economic growth in Greece: Empirical evidence from their cyclical components

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    This paper examines the relationship between the cyclical components of Greek GDP and international tourism income for Greece for the period 1976–2004. Using spectral analysis the authors find that cyclical fluctuations of GDP have a length of about nine years and that international tourism income has a cycle of about seven years. The volatility of tourism income is more than eight times the volatility of the Greek GDP cycle. VAR analysis shows that the cyclical component of tourism income is significantly influencing the cyclical component of GDP in Greece. The findings support the tourism-led economic growth hypothesis and are of particular interest and importance to policy makers, financial analysts and investors dealing with the Greek tourism industry

    Kaon decay interferometry as meson dynamics probes

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    We discuss the time dependent interferences between KLK_L and KSK_S in the decays in 3π3\pi and ππγ\pi\pi\gamma, to be studied at interferometry machines such as the ϕ\phi-factory and LEAR. We emphasize the possibilities and the advantages of using interferences, in comparison with width measurements, to obtain information both on CPCP conserving and CPCP violating amplitudes. Comparison with present data and suggestions for future experiments are made.Comment: 15 pages, in RevTex, Report INFNNA-IV-93-31, UTS-DFT-93-2
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