12,641 research outputs found

    Magnetic frustration in BaCuSi2O6 released

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    Han Purple (BaCuSi2O6) is not only an ancient pigment, but also a valuable model material for studying Bose-Einstein condensation (BEC) of magnons in high magnetic fields. Using precise low-temperature structural data and extensive density-functional calculations, we elucidate magnetic couplings in this compound. The resulting magnetic model comprises two types of nonequivalent spin dimers, in excellent agreement with the (63,65)Cu nuclear magnetic resonance data. We further argue that leading interdimer couplings connect the upper site of one dimer to the bottom site of the contiguous dimer, and not the upper-to-upper and bottom-to-bottom sites, as assumed previously. This finding is verified by inelastic neutron scattering data and implies the lack of magnetic frustration in BaCuSi2O6, thus challenging existing theories of the magnon BEC in this compound.Comment: 4.5 pages, 4 figures, 1 tabl

    Enhancing the Benefits for Developing Countries in the Doha Development Agenda Negotiations

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    This is a position paper dealing with the major issues of the Doha Round negotiations that are of importance for developing countries. It was prepared for circulation prior to the Cancun Ministerial Meeting of the WTO. It provides recommendations for WTO decision making, agricultural policies, market access, intellectual property, services, the Singapore issues, technical assistance, and special treatment. These are accompanied by brief arguments in support of these recommendations.

    Globalization’s Bystanders: Does Trade Liberalization Hurt Countries that Do Not Participate?

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    This paper uses trade theory to examine the effects of trade liberalization on countries that do not participate in it. These include both countries that fail to participate in multilateral trade negotiations, and also countries that lie outside of preferential trading arrangements such as free trade areas. The analysis suggests that, while it is theoretically possible for excluded countries to gain, through improved terms of trade, from trade liberalization, several reasons suggest that they are more likely to lose.Trade liberalization, Globalization

    Designing a Pro-Active Stance for India in the Doha Development Agenda Negotiations

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    In this paper, we first summarize the framework that has been agreed upon as the basis for the WTO Doha Development Agenda (DDA) negotiations. We then discuss briefly the design and mission of the WTO and the economic effects of multilateral trade liberalization. Thereafter, we discuss the conditions for India’s realization of the maximum benefits from the DDA negotiations and the implications for broader Indian domestic policy reforms. We then set out our recommendations for India’s pro-active involvement and negotiating strategies in the DDA negotiations for multilateral trade liberalization in agricultural products, manufactures, and services, and for improvements in WTO rules governing trade and related issues. We conclude with a brief discussion of the policy agenda adopted by India’s newly elected coalition parties, the implications of the emphasis on social reform and equity for India’s negotiating strategies in the DDA negotiations, and a vision of the role that India might play in the global trading system and in world politics.

    Tests of non-standard electroweak couplings of right-handed quarks

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    The standard model can be interpreted as the leading order of a Low-Energy Effective Theory (LEET) invariant under a higher non linearly realized symmetry SnatSU(2)W×U(1)YS_{nat}\supset SU(2)_W \times U(1)_Y equipped with a systematic power counting. Within the minimal version of this ``not quite decoupling'' LEET, the dominant non-standard effect appears at next-to-leading order (NLO) and is a modification of the couplings of fermions to W and Z. In particular, the coupling of right-handed quarks to Z is modified and a direct coupling of right-handed quarks to W emerges. Charged right-handed lepton currents are forbidden by an additional discrete symmetry in the lepton sector originally designed to suppress Dirac neutrino masses. A complete NLO analysis of experimental constraints on these modified couplings is presented. Concerning couplings of light quarks, the interface of the electroweak tests with QCD aspects is discussed in detail.Comment: 56 pages, 14 figures, v2: references added, minor modifications in the text, accepted for publication in JHE

    EU Expansion and EU Growth

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    Almost from its inception as the European Economic Community, the European Union has excited the hope if not the expectation that it would generate dynamic gains from trade, including perhaps a permanent increase in the rates of growth of participating countries. This paper examines the empirical evidence relating to this issue and then interprets the economic performance of the EU countries in terms of a simple theoretical model of economic integration with increasing returns to scale. The paper concludes that evidence for increased long-run growth rates of the EU countries is weak, and that what may have happened instead is that countries have benefited asymmetrically from the formation and the later expansion of the EU. Benefits of economic integration appear to accrue - in the form of temporarily higher growth rates leading to higher levels of per capita income - first to large countries and then to some smaller countries that entered the arrangement relatively early.European integration, Trade and growth

    Enhancing the Benefits for India and Other Developing Countries in the Doha Development Agenda Negotiations

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    The Doha Round of multilateral trade negotiations in the World Trade Organization (WTO) has been billed from the start as the “Doha Development Agenda,” with the promise in the Doha Ministerial Declaration to “place [developing countries’] needs and interests at the heart of the Work Programme adopted in this Declaration.” The reason for this emphasis was in part the perception that previous rounds had neglected the interests of developing countries or, in the case of the Uruguay Round, had brought developing countries on board with promises that were misleading or not likely to be kept. The collapse of the September 2003 Cancun Ministerial Meeting reinforced the need to address the interests of developing countries, and recent agreements reached at the WTO in Geneva suggest that the Doha negotiations may now be on track. What is now important to emphasize, as the negotiations get under way, is to follow through with actions that are designed to fulfill the special needs of developing countries and to address their problems in implementing these actions. In our paper we lay out what we believe to be the most important actions that could be taken in the Doha Round for the benefit of developing countries, including India. We base these suggestions primarily on the understanding of the economics of international trade that has been developed over the last two centuries and is widely taught in the universities of the world, and also on the research in recent years dealing with specific aspects of trade negotiations in general and of the Doha Round in particular. With regard to the interests of developing countries generally, we provide recommendations for WTO decision-making, agricultural policies, market access, intellectual property, services, the Singapore issues, technical assistance, and special treatment. Each of these recommendations is accompanied by brief arguments in support. The paper then goes on to review several more specific policy and negotiating recommendations focused on India. It is essential that India and other developing countries participate actively and constructively in the Doha negotiations to further their own interests. They cannot rely on the best-intentioned developed countries to do this for them, since the developed countries will inevitably find themselves making compromises in favor of their own interests and in response to powerful pressures from their domestic constituents. Many developing countries are at a disadvantage in the negotiating process, due to their resource limitations, and in many cases due also to their inexperience in negotiations. Offsetting these disadvantages, however, are their large numbers and the compelling case that can be made for meeting their needs. What the developing countries need is leadership and cooperation, which India is well suited to provide. What is also needed is a willingness to listen and be flexible on the part of their developed country counterparts.
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