1,805 research outputs found

    Multifunction MMIC For Miniaturized Solid State Switch Matrix

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    This paper describes a new multifunction MMIC expressly designed for a reconfiguration matrix equipment.This MMIC has been developed using a standard PHEMT process and includes two switches,a totally switchable-off amplifier and a temperature compensation circuit.The complete circuit has also been designed to interface a standard CMOS control level. Performed simulations and obtained results demonstrate the effectiveness of this approach in reaching compactness and reliability of satellite equipment

    Overview of progress in neutrino scattering measurements

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    Recent progress in neutrino scattering experiments with few GeV neutrino beams is reviewed, focusing on new experimental input since the beginning of the NuInt workshop series in 2001. Progress in neutrino quasi-elastic scattering, resonance production, coherent pion production, scattering in the transition region between the resonance and deep inelastic regimes, and nuclear effects in neutrino-nucleus scattering, is discussed.Comment: To appear in the proceedings of 5th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia, Illinois, 30 May - 3 Jun 2007. Submitted to AIP Conf.Pro

    Effects of anisotropy in a nonlinear crystal for squeezed vacuum generation

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    Squeezed vacuum (SV) can be obtained by an optical parametric amplifier (OPA) with the quantum vacuum state at the input. We are interested in a degenerate type-I OPA based on parametric down-conversion (PDC) where due to phase matching requirements, an extraordinary polarized pump must impinge onto a birefringent crystal with a large \chi(2) nonlinearity. As a consequence of the optical anisotropy of the medium, the direction of propagation of the pump wavevector does not coincide with the direction of propagation of its energy, an effect known as transverse walk-off. For certain pump sizes and crystal lengths, the transverse walk-off has a strong influence on the spatial spectrum of the generated radiation, which in turn affects the outcome of any experiment in which this radiation is employed. In this work we propose a method that reduces the distortions of the two-photon amplitude (TPA) of the states considered, by using at least two consecutive crystals instead of one. We show that after anisotropy compensation the TPA becomes symmetric, allowing for a simple Schmidt expansion, a procedure that in practice requires states that come from experimental systems free of anisotropy effects

    Understanding the Forward Muon Deficit in Coherent Pion Production

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    For any inelastic process v+I+Fv_{\ell} + I \to \ell^- + F with m=0m_{\ell} = 0, the cross section at θ=0\theta_{\ell} = 0 is given by Adler's PCAC theorem. Inclusion of the lepton mass has a dynamical effect (``PCAC-screening'') caused by interference of spin-zero (π+\pi^+) and spin-one exchanges. This effect may be relevant to the forward suppression reported in recent experiments.Comment: 3 pages, 2 figures, presented at NuInt07, Fermilab, may 31 - june 3 200

    Compensation of anisotropy effects in the generation of two-photon light

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    We analyse a method to compensate for anisotropy effects in the spatial distribution of parametric down-conversion (PDC) radiation in bulk crystals. In this method, a single nonlinear crystal is replaced by two consecutive crystals with opposite transverse walk-off directions. We implement a simple numerical model to calculate the spatial distribution of intensity and correlations, as well as the Schmidt mode structure, with an account for the anisotropy. Experimental results are presented which prove the validity of both the model and the method.Comment: 9 pages, 8 figure

    Neutral Current π0\pi^0 Production in MiniBooNE

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    This paper describes the analysis used to determine the neutral current π0\pi^0 production in MiniBooNE in bins of momentum. Additionally, a measurement of the relative coherent production of π0\pi^0s is discussed. The coherent production rate is found to be (19.5 ±\pm1.1 (stat) ±\pm2.5 (sys))% of the total exclusive neutral current π0\pi^0 production rate.Comment: Prepared for the Proceedings of Neutrino Interactions 200

    Pion Production in Neutrino-Nucleon Reactions

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    We construct a model for the weak pion production off the nucleon, which in addition to the weak excitation of the Δ(1232)\Delta(1232) resonance and its subsequent decay into NπN\pi, it includes also some background terms required by chiral symmetry. We re-fit the C5A(q2)C_5^A(q^2) form factor to the flux averaged νμpμpπ+\nu_\mu p \to \mu^-p\pi^+ ANL q2q^2-differential cross section data, finding a substantially smaller contribution of the Δ\Delta pole mechanism than traditionally assumed in the literature. We also show that the interference between the Delta pole and the background terms produces parity-violating contributions to the pion angular differential cross section.Comment: To appear in the proceedings of Fifth International Workshop on. Neutrino-Nucleus Interactions in the Few-GeV Region. May 30, 2007 - June 3, 2007. Fermilab, Batavia, Illinois US

    Spectral functions for medium-sized nuclei

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    The spectral functions for calcium and argon are constructed. It is verified that their predictions for the quasielastic electron-nucleus cross sections in the energy range ~1 GeV agree with the data. The argon spectral function is then used to obtain the quasielastic neutrino-nucleus cross section.Comment: 3 pages, 3 figures, presented at 5th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Fermilab, USA, 30.05-3.06.200
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