1,159 research outputs found

    Soft Colour Interactions in Non-perturbative QCD

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    Improved understanding of non-perturbative QCD dynamics can be obtained in terms of soft colour exchange models. Their essence is the variation of colour string-field topologies giving a unified description of final states in high energy interactions. In particular, both events with and without large rapidity gaps are obtained in agreement with data from ep at HERA and ppbar at the Tevatron, where also the surprisingly large production rate of high-p_T charmonium and bottomonium is reproduced.Comment: 4 pages, contribution to PANIC 99 conference proceedings, to appear in Nucl. Phys. A. Uses espcrc1.st

    Rapidity Gaps from Colour String Topologies

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    Diffractive deep inelastic scattering at HERA and diffractive W and jet production at the Tevatron are well described by soft colour exchange models. Their essence is the variation of colour string-field topologies giving both gap and no-gap events, with a smooth transition and thereby a unified description of all final states.Comment: 3 pages, 6 eps figures, contribution to the DIS 99 workshop proceedings, uses npb.st

    Moving At-Risk Teenagers Out of High-Risk Neighborhoods: Why Girls Fare Better Than Boys

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    neighborhood effects; social experiment; mixed methods; youth risk behavior

    Hard colour singlet exchange and gaps between jets at the Tevatron

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    The new kind of events with a rapidity gap between two high-E_T jets, observed in high energy ppbar collisions at the Tevatron, is found to be well described by the exchange of a colour singlet gluon system in the BFKL framework. This requires going beyond the conventional asymptotic Mueller-Tang approximation, which results in qualitatively different features of the basic parton-parton scattering amplitude. Non-leading corrections to the BFKL equation are included by incorporation of the consistency constraint and the running QCD coupling. Hadronisation and other non-perturbative QCD effects are treated through a complete Monte Carlo simulation, providing a gap survival probability that varies event-by-event, facilitating comparison with experimental results.Comment: 15 pages, 11 eps figure

    Decisive test for the Pomeron at Tevatron

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    We propose a new measurement to be performed at the Tevatron which can be decisive to distinguish between Pomeron-based and soft color interaction models of hard diffractive scattering.Comment: 5 pages, 3 figures, 1 tabel revtex forma

    Diffractive Higgs boson production at the Tevatron and LHC

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    Improved possibilities to find the Higgs boson in diffractive events, having less hadronic activity, depend on whether the cross section is large enough. Based on the soft color interaction models that successfully describe diffractive hard scattering at HERA and the Tevatron, we find that only a few diffractive Higgs events may be produced at the Tevatron, but we predict a substantial rate at the LHC.Comment: 4 pages, 4 figures, uses Revtex

    Energy Dependence of the Contribution of Pion Exchange to Large-Rapidity-Gap Events in Deep Inelastic Scattering

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    We study the energy dependence of the contribution of pion exchange to large-rapidity-gap events in deep inelastic scattering. The results show that this contribution can be quite significant at low energy and that the LRG events observed by E665 collaboration in \mu Xe and \mu D interactions at 490 GeVGeV can be reasonably well described in terms of meson exchange. We also show that the distribution of the maximum rapidity for all hadrons is quite different from that for charged hadrons only and that the former exhibits also shoulder-like structure for events at 490 GeVGeV similar to that at HERA.Comment: 12 pages, 4 figures, Phys. Rev. D (in press

    PRESIDENCIA DE LA PLAZA Y MACHAGAI. Análisis comparativo del proceso territorial desarrollado en el centro este chaqueño.

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    El propósito de esta investigación ha sido comparar dos espacios vecinos situados en el centro este de la provincia del Chaco. El análisis desarrollado se centró en la evolución geohistórica, en la conformación político-institucional y en los caracteres naturales, demográficos, económicos y socioculturales de los departamentos de Presidencia de la Plaza y 25 de Mayo. Como resultado de ello, puede decirse que se trata de un espacio que ha sido el ámbito natural de los pueblos originarios qom y moqoit hasta fines del siglo XIX, cuando el ejército argentino emplazó fortines en la zona. Algunos ganaderos provenientes del norte santafesino se instalaron en el área, aprovechando la presencia militar y los trabajos previos al trazado del ferrocarril Central Norte Argentino. El dinamismo demográfico y económico se dio a partir de 1912, cuando los trenes comenzaron a unir Barranqueras con el Km 173 (Presidencia Roque Sáenz Peña), con paradas en los desvíos Km 109 (Presidencia de la Plaza) y Km 129 (Machagai). La explotación forestal fue una actividad importante al iniciarse el proceso, pero entre las décadas de 1920 y 1960 tomó relevancia el cultivo del algodón. En el área rural, tras la crisis de esa actividad agrícola, se expandió la ganadería bovina extensiva y, luego de los años ochenta, las cabeceras departamentales arraigaron a la industria forestal

    The narratives of Hardship: : The new and the old poor in the aftermath of the 2008 crisis in Europe

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    This document is the Accepted Manuscript version of the following article: Hulya Dagdeviren, Matthew Donoghue, and Lars Meier, ‘The narratives of hardship: the new and the old poor in the aftermath of the 2008 crisis in Europe’, The Sociological Review, vol. 65 (2): 369-385, May 2017. The final, definitive version of record is available online at doi: https://doi.org/10.1111/1467-954X.12403. Published by SAGE.This paper examines poverty and hardship in Europe after the 2008 crisis, using household interviews in nine European countries. A number of findings deserve highlighting. First, making a distinction between ‘the old poor’ (those who lived in poverty before as well as after the crisis) and ‘the new poor’ (thosewho fell into hardship after the crisis), we show that hardship is experienced quite differently by these groups. Second, the household narratives showed that while material deprivations constitute an important aspect of hardship, the themes of insecurity and dependency also emerged as fundamental dimensions. In contrast to popular political discourse in countries such as the UK, dependency on welfare or family was experienced as a source of distress and manifested as a form of hardship by participants in all countries covered in this study.Peer reviewedFinal Accepted Versio

    Second language user support

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    Computer users rarely experience entirely trouble-free interaction. The natural variety ofindividuals ensures that no software systems yield constantly fluent interaction for allusers. In consequence, software designers often strive to ameliorate this situation bybuilding 'user support' into their systems. User support can take different forms but,conventionally, each aims to assist the needy end-user by means of facilities directly supporting the performance of certain operations, or through supply of information thatadvises the user on available system functionality.The present paper briefly characterises a range of user support facilities before describingone requirement in greater detail. This aspect considers the needs of users whose mother-tongue is not English, but who are obliged to use English-based information systems. Inthis context, 'helping the user' must reasonably extend beyond mere advice on systemoperation to selective elucidation of information content. We regard this move as alogical extension of the user support concept, by seeking to address specific interactionneeds in a target user population. An example of this approach is described through aninformation system, in the domain of civil engineering, for native Chinese speakers ofEnglish
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