27,652 research outputs found

    The Law and Policy of Civil Rights: A Tactical Perspective for Educators

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    This article is presented to share with fellow professional teacher-scholars the preparation of a freshly-formulated teaching project. The aim of this project is to provide a classroom public policy study program wherein students debate policy issues in a carefully structured and professional fashion. This structure encompasses hands-on study of actually-litigated minority set-aside/affirmative action controversies before the U.S. Supreme Court, with every student always utilizing the primary documents (the litigants\u27 briefs) used by the Supreme Court Justices themselves. These briefs provide readymade resources fueling policy debate on either side of each case

    Equation of state of strongly coupled Hamiltonian lattice QCD at finite density

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    We calculate the equation of state of strongly coupled Hamiltonian lattice QCD at finite density by constructing a solution to the equation of motion corresponding to an effective Hamiltonian using Wilson fermions. We find that up to and beyond the chiral symmetry restoration density the pressure of the quark Fermi sea can be negative indicating its mechanical instability. This result is in qualitative agreement with continuum models and should be verifiable by future numerical simulations.Comment: 14 pages, 2 EPS figures. Revised version - added discussion on the equation of stat

    Sum rules in the heavy quark limit of QCD

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    In the leading order of the heavy quark expansion, we propose a method within the OPE and the trace formalism, that allows to obtain, in a systematic way, Bjorken-like sum rules for the derivatives of the elastic Isgur-Wise function ξ(w)\xi(w) in terms of corresponding Isgur-Wise functions of transitions to excited states. A key element is the consideration of the non-forward amplitude, as introduced by Uraltsev. A simplifying feature of our method is to consider currents aligned along the initial and final four-velocities. As an illustration, we give a very simple derivation of Bjorken and Uraltsev sum rules. On the other hand, we obtain a new class of sum rules that involve the products of IW functions at zero recoil and IW functions at any ww. Special care is given to the needed derivation of the projector on the polarization tensors of particles of arbitrary integer spin. The new sum rules give further information on the slope ρ2=ξ(1)\rho^2 = - \xi '(1) and also on the curvature σ2=ξ(1)\sigma^2 = \xi '' (1), and imply, modulo a very natural assumption, the inequality σ254ρ2\sigma^2 \geq {5\over 4} \rho^2, and therefore the absolute bound σ21516\sigma^2 \geq {15 \over 16}.Comment: 64 pages, Late

    A "BPS expansion" for B and D mesons

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    We analyze consequences of the approximation \mu_\pi^2 -\mu_G^2 << \mu_\pi^2 (a `BPS' limit) for B and D mesons. It is shown that neglecting perturbative effects many power corrections would vanish to all orders in 1/m_Q, in particular those violating heavy flavor symmetry. Among them are corrections to B->D formfactors. A number of relations receive corrections only to the second order expanding around the BPS limit to any order in 1/m_Q, including both f_+ and f_- at zero recoil. This allows an accurate evaluation of {\cal F}_+ for B->D l\nu. Its perturbative renormalization is computed analytically in the required Wilsonian scheme, yielding the dominant 3% enhancement.Comment: 13 pages, LaTeX, two figure

    Critical exponents predicted by grouping of Feynman diagrams in phi^4 model

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    Different perturbation theory treatments of the Ginzburg-Landau phase transition model are discussed. This includes a criticism of the perturbative renormalization group (RG) approach and a proposal of a novel method providing critical exponents consistent with the known exact solutions in two dimensions. The usual perturbation theory is reorganized by appropriate grouping of Feynman diagrams of phi^4 model with O(n) symmetry. As a result, equations for calculation of the two-point correlation function are obtained which allow to predict possible exact values of critical exponents in two and three dimensions by proving relevant scaling properties of the asymptotic solution at (and near) the criticality. The new values of critical exponents are discussed and compared to the results of numerical simulations and experiments.Comment: 34 pages, 6 figure

    Bulletin No. 224 - Muck Soil Investigations: Progress Report, Sanpete County Experimental Farm 1927-30, Inclusive

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    The estimated area of muck or peat soil in Utah is approximately 21,000 acres. The muck occurs in many valleys of Utah. The largest areas are in the Sanpete and Utah Lake Valleys. The area in the former is estimated at 6500 acres and the Utah Valley area at 9000 acres; the other areas, all more or less significant in size, are scattered throughout the state. Investigations reported have been confined entirely to the Sanpete area which is located near the south and bottom end of the valley and is west of the towns of Chester, Ephraim, and Manti. During part of the year the lands involved are subject to overflow by the San Pitch River. Water covers most of the area early in the winter and during the spring months high water keeps it submerged until June. Before the neighboring communities were settled by white people, the area was probably submerged the greater part of the year. As the section developed, most of the water from the San Pitch River was diverted for irrigation purposes, resulting in an annual decrease of water which reached the swamp

    The Nature of the Low-Metallicity ISM in the Dwarf Galaxy NGC 1569

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    We are modeling the spectra of dwarf galaxies from infrared to submillimeter wavelengths to understand the nature of the various dust components in low-metallicity environments, which may be comparable to the ISM of galaxies in their early evolutionary state. The overall nature of the dust in these environments appears to differ from those of higher metallicity starbursting systems. Here, we present a study of one of our sample of dwarf galaxies, NGC 1569, which is a nearby, well-studied starbursting dwarf. Using ISOCAM, IRAS, ISOPHOT and SCUBA data with the Desert et al. (1990) model, we find consistency with little contribution from PAHs and Very Small Grains and a relative abundance of bigger colder grains, which dominate the FIR and submillimeter wavelengths. We are compelled to use 4 dust components, adding a very cold dust component, to reproduce the submillimetre excess of our observations.Comment: 4 pages, 4 postscript figures. Proceedings of "Infrared and Submillimeter Astronomy. An International Colloquium to Honor the Memory of Guy Serra" (2002

    Birds in a partly clearfelled dry eucalypt forest on dolerite in southeastern Tasmania

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    An area of dry eucalypt forest on dolerite in southeastern Tasmania was clearfelled in 1981. A portion of this area was subsequently slash-burnt and aerially sown in 1982, whilst the rest of the area was left unburnt and unsown. A monthly bird census was conducted during 1983-1984 in surrounding uncut, mature forest and also on the clearfelled area. Species were recorded together with the habitat in which they occurred and the particular plant species being utilised. A total of 46 avian species were recorded during the monthly censuses, with most species and individuals being observed in the spring months. The numbers of species and individuals recorded on the burnt and unburnt clearfelled areas were low in comparison with those observed in the uncut forest. In general, those species able to utilise open-ground habitats tended to be the least affected by clearfelling followed by slash-burning. However, the unburnt clearfelled area provided foraging sites for certain species, in preference to the nearby slash-burnt area. Many individuals recorded in the clearfelled areas made use of trees left standing after logging. The use of fire in dry forest management practice and the importance of cull trees are discussed
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