37,521 research outputs found

    Maximum-likelihood estimation of delta-domain model parameters from noisy output signals

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    Fast sampling is desirable to describe signal transmission through wide-bandwidth systems. The delta-operator provides an ideal discrete-time modeling description for such fast-sampled systems. However, the estimation of delta-domain model parameters is usually biased by directly applying the delta-transformations to a sampled signal corrupted by additive measurement noise. This problem is solved here by expectation-maximization, where the delta-transformations of the true signal are estimated and then used to obtain the model parameters. The method is demonstrated on a numerical example to improve on the accuracy of using a shift operator approach when the sample rate is fast

    Feasibility studies of the time-like proton electromagnetic form factor measurements with PANDA at FAIR

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    The possibility of measuring the proton electromagnetic form factors in the time-like region at FAIR with the \PANDA detector is discussed. Detailed simulations on signal efficiency for the annihilation of pˉ+p\bar p +p into a lepton pair as well as for the most important background channels have been performed. It is shown that precision measurements of the differential cross section of the reaction pˉ+pe++e\bar p +p \to e^++ e^- can be obtained in a wide angular and kinematical range. The individual determination of the moduli of the electric and magnetic proton form factors will be possible up to a value of momentum transfer squared of q214q^2\simeq 14 (GeV/c)2^2. The total pˉ+pe++e\bar p +p\to e^++e^- cross section will be measured up to q228q^2\simeq 28 (GeV/c)2^2. The results obtained from simulated events are compared to the existing data. Sensitivity to the two photons exchange mechanism is also investigated.Comment: 12 pages, 4 tables, 8 figures Revised, added details on simulations, 4 tables, 9 figure

    The LHCb Upgrade

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    The LHCb detector has been designed to study CP violation and other rare phenomena in B-meson decays up to a luminosity of 5.1032cm2s1\sim 5.10^{32}\rm cm^{-2}s^{-1}. This paper will describe what is limiting LHCb to exploit the much higher luminosities available at the LHC, and what are the baseline modifications which will remedy these limitations. The aim of SuperLHCb is to increase the yields in hadronic B-decay channels by about a factor twenty compared to LHCb, while for channels with leptons in the final state a factor ten increase in statistics is envisaged.Comment: Flavor Physics & CP Violation Conference, Bled, 200

    Resonant Structure of τ3ππ0ντ\tau\to 3\pi\pi^{0}\nu_{\tau} and τωπντ\tau\to \omega\pi\nu_{\tau} Decays

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    The resonant structure of the four pion final state in the decay τ3ππ0ντ\tau \to 3\pi\pi^0\nu_\tau is analyzed using 4.27 million τ+τ\tau^+\tau^- pairs collected by the CLEO II experiment. We search for second class currents in the decay τωπντ\tau \to \omega\pi\nu_\tau using spin-parity analysis and establish an upper limit on the non-vector current contribution. The mass and width of the ρ\rho' resonance are extracted from a fit to the τωπντ\tau \to \omega\pi\nu_\tau spectral function. A partial wave analysis of the resonant structure of the τ3ππ0ντ\tau \to 3\pi\pi^0\nu_\tau decay is performed; the spectral decomposition of the four pion system is dominated by the ωπ\omega\pi and a1πa_1 \pi final states.Comment: 34 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN
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