7,184 research outputs found

    Characterization of photomultiplier tubes in a novel operation mode for Secondary Emission Ionization Calorimetry

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    Hamamatsu single anode R7761 and multi-anode R5900-00-M16 Photomultiplier Tubes have been characterized for use in a Secondary Emission (SE) Ionization Calorimetry study. SE Ionization Calorimetry is a novel technique to measure electromagnetic shower particles in extreme radiation environments. The different operation modes used in these tests were developed by modifying the conventional PMT bias circuit. These modifications were simple changes to the arrangement of the voltage dividers of the baseboard circuits. The PMTs with modified bases, referred to as operating in SE mode, are used as an SE detector module in an SE calorimeter prototype, and placed between absorber materials (Fe, Cu, Pb, W, etc.). Here, the technical design of different operation modes, as well as the characterization measurements of both SE modes and the conventional PMT mode are reported

    The design of a dam and the investigation of a water supply for the city of Rolla, Missouri

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    The object of this paper is to investigate a means of supplying the City of Rolla with better water at a reasonable a price as possible. The elevation and distance of the supply from the city were very important factors,also the most economical position for the dam was to be considered. After examining several drainage basins with the above purposes in mind we selected one just west of the City on account of its convenience and high elevation. The watershed includes an area of ever eight hundred acres and is divided into two parts which come together in a narrow valley between two prominent hills --Introduction, page 1

    Four-fermion production in e+ee^+ e^- collisions at centre-of-mass energies of 130 and 136 GeV

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    Four-fermion events have been selected in a data sample of 5.8 pb**-1 collected with the ALEPH detector at centre-of-mass energies of 130 and 136 GeV. The final states l^+l^- qqbar, l^+l^-l^+l^-, nunubar qqbar, and nunubar l^+l^- have been examined. Five events are observed in the data, in agreement with the Standard Model predictions of 6.67 +/- 0.38 events from four-fermion processes and 0.14+0.19-0.05 from background processes

    Scaling in many-body systems and proton structure function

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    The observation of scaling in processes in which a weakly interacting probe delivers large momentum q{\bf q} to a many-body system simply reflects the dominance of incoherent scattering off target constituents. While a suitably defined scaling function may provide rich information on the internal dynamics of the target, in general its extraction from the measured cross section requires careful consideration of the nature of the interaction driving the scattering process. The analysis of deep inelastic electron-proton scattering in the target rest frame within standard many-body theory naturally leads to the emergence of a scaling function that, unlike the commonly used structure functions F1F_1 and F2F_2, can be directly identified with the intrinsic proton response.Comment: 11 pages, 4 figures. Proceedings of the 11th Conference on Recent Progress in Many-Body Theories, Manchester, UK, July 9-13 200

    Hadronic polarization in neutrino scattering

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    "Economic results achieved by a selected group of organic farms in Poland in 2004"

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    Abstract: Organic farming is becoming more and more popular among Polish farmers. In the year of the accession of Poland to the European Union, the number of certified organic farms amounted to 1683. By the end of 2005, which is after the first year of Poland’s membership in the EU, the number of farms practicing exclusively organic farming or taking up that course of production amounted to more than 7000. On the basis of agricultural accountancy from 2004, an economic and production evaluation of 110 organic farms included in the Polish FADN sample was carried out. The organic farms were classified into 5 classes of economic size. 92% of them were of economic size below 16 ESU. The study contains economic and production results achieved by a group of farms belonging to the principal type TF60 “Mixed cropping” and included in the type TF8 „Field crops”

    Four-jet angular distributions and color charge measurements: leading order versus next-to-leading order

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    We present the next-to-leading order perturbative QCD prediction to the four-jet angular distributions used by experimental collaborations at LEP for measuring the QCD color charge factors. We compare our results to ALEPH data corrected to parton level. We perform a leading order ``measurement'' of the QCD color factor ratios by fitting the leading order perturbative predictions to the next-to-leading order result. Our result shows that in an experimental analysis for measuring the color charge factors the use of the O(αs3\alpha_s^3) QCD predictions instead of the O(αs2\alpha_s^2) results may shift the center of the fit by a relative factor of 1+2\as in the TR/CFT_R/C_F direction.Comment: 14 pages, 10 tables, 5 figures, revtex, eps style

    Light Front Formalism for Composite Systems and Some of Its Applications in Particle and Relativistic Nuclear Physics

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    Light front formalism for composite systems is presented. Derivation of equations for bound state and scattering problems are given. Methods of constructing of elastic form factors and scattering amplitudes of composite particles are reviewed. Elastic form factors in the impulse approximation are calculated. Scattering amplitudes for relativistic bound states are constructed. Some model cases for transition amplitudes are considered. Deep inelastic form factors (structure functions) are expressed through light front wave functions. It is shown that taking into account of transverse motion of partons leads to the violation of Bjorken scaling and structure functions become square of transverse momentum dependent. Possible explanation of the EMC-effect is given. Problem of light front relativization of wave functions of lightest nuclei is considered. Scaling properties of deuteron, 3He{}^3He and 4He{}^4He light front wave functions are checked in a rather wide energy range.Comment: Review paper, Submitted to Phys. Rep., 89 pages, 23 figure

    The BFKL Pomeron in 2+1 Dimensional QCD

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    We investigate the high-energy scattering in the spontaneously broken Yang - Mills gauge theory in 2+1 space--time dimensions and present the exact solution of the leading lns\ln s BFKL equation. The solution is constructed in terms of special functions using the earlier results of two of us (L.N.L. and L.S.). The analytic properties of the tt-channel partial wave as functions of the angular momentum and momentum transfer have been studied. We find in the angular momentum plane: (i) a Regge pole whose trajectory has an intercept larger than 1 and (ii) a fixed cut with the rightmost singularity located at j=1j=1. The massive Yang - Mills theory can be considered as a theoretical model for the (non-perturbative) Pomeron. We study the main structure and property of the solution including the Pomeron trajectory at momentum transfer different from zero. The relation to the results of M. Li and C-I. Tan for the massless case is discussed.Comment: 28 pages LATEX, 3 EPS figures include
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