2,211 research outputs found

    Electromagnetic interactions for the two-body spectator equations

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    This paper presents a new non-associative algebra which is used to (i) show how the spectator (or Gross) two-body equations and electromagnetic currents can be formally derived from the Bethe-Salpeter equation and currents if both are treated to all orders, (ii) obtain explicit expressions for the Gross two-body electromagnetic currents valid to any order, and (iii) prove that the currents so derived are exactly gauge invariant when truncated consistently to any finite order. In addition to presenting these new results, this work complements and extends previous treatments based largely on the analysis of sums of Feynman diagrams.Comment: 44 pages, 14 figure

    Factorization Breaking of AdTA^T_d for polarized deuteron targets in a relativistic framework

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    We discuss the possible factorization of the tensor asymmetry AdTA^T_d measured for polarized deuteron targets within a relativistic framework. We define a reduced asymmetry and find that factorization holds only in plane wave impulse approximation and if p-waves are neglected. Our numerical results show a strong factorization breaking once final state interactions are included. We also compare the d-wave content of the wave functions with the size of the factored, reduced asymmetry and find that there is no systematic relationship of this quantity to the d-wave probability of the various wave functions

    Quark-Hadron Duality

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    Quark-hadron duality and its potential applications are discussed. We focus on theoretical efforts to model duality.Comment: Plenary Talk given at Baryons 2002, Newport News, VA, March 200

    Lagrangian with off-shell vertices and field redefinitions

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    Meson exchange diagrams following from a lagrangian with off-shell meson-nucleon couplings are compared with those generated from conventional dynamics. The off-shell interactions can be transformed away with the help of a nucleon field redefinition. Contributions to to the NNNN- and 3N3N-potentials and nonminimal contact e.m. meson-exchange currents are discussed, mostly for an important case of scalar meson exchange. (pacs 11.10.Lm, 13.75.Cs, 21.30.-x, 24.10.Jv)Comment: 18 pages (Revtex), 4 eps figure

    Classroom Management in the Urban Setting

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    The management in an urban setting can be difficult when the proper actions and modifications are not put in place. Administrators and further more, the school district needs to put specific expectations in place and consequences that are fair and appropriate to the background of the students that they are helping. Diversity amongst urban students is apparent and needs to be recognized by the teachers and administration in the urban setting. Teachers who are properly informed of what the expectations are and the consequences that follow, will also carry those and some of their own expectations and consequences out in their classroom. These teachers that follow the district policies, which needs to be fair and consistent, will be shown through their classroom, which looks like an organized, routine structured, and well managed classroom. Without proper expectations and support from the district and administration, a well managed urban classroom is out of reach

    Britain’s departure from “Ever Closer Union” is of great significance

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    The expression “ever closer union” remains a driving force of European integration of the federalist kind, writes Geoffrey Van Orden MEP, who took part in the expert proceedings on the topic at the LSE Commission on the Future of Britain in Europe. This is why if the UK were to decide to remain in the EU after 23 June, the reform package secured by David Cameron in this area could be of great significance. However, this would have to be accompanied by real political drive on the part of UK government, in order to exploit opportunities and resist the inevitable moves by others towards greater integration
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