9,305 research outputs found

    CP1CP^{1} model with Hopf term and fractional spin statistics

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    We reconsider the CP1CP^{1} model with the Hopf term by using the Batalin-Fradkin-Tyutin (BFT) scheme, which is an improved version of the Dirac quantization method. We also perform a semi-classical quantization of the topological charge Q sector by exploiting the collective coordinates to explicitly show the fractional spin statistics.Comment: 15 page

    Symmetries of SU(2) Skyrmion in Hamiltonian and Lagrangian approaches

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    We apply the Batalin-Fradkin-Tyutin (BFT) method to the SU(2) Skyrmion to study the full symmetry structure of the model at the first class Hamiltonian level. On the other hand, we also analyze the symmetry structure of the action having the WZ term, which corresponds to this Hamiltonian, in the framework of the Lagrangian approach. Furthermore, following the BFV formalism we derive the BRST invariant gauge fixed Lagrangian from the above extended action.Comment: 14 pages, final revised version, to appear in Mod. Phys. Lett.

    Flavor symmetry breaking effects on SU(3) Skyrmion

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    We study the massive SU(3) Skyrmion model to investigate the flavor symmetry breaking (FSB) effects on the static properties of the strange baryons in the framework of the rigid rotator quantization scheme combined with the improved Dirac quantization one. Both the chiral symmetry breaking pion mass and FSB kinetic terms are shown to improve cc the ratio of the strange-light to light-light interaction strengths and cˉ\bar{c} that of the strange-strange to light-light.Comment: 12 pages, latex, no figure

    Pathways to Careers in Health Care

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    The Patient Protection and Affordable Care Act passed by Congress and signed into law by President Barack Obama in 2010 effected major changes in the financing and delivery of health care in the United States. It also authorized creation of the Health Profession Opportunity Grants program (HPOG), a demonstration effort within the U.S. Department of Health and Human Services to provide opportunities for education and training that lead to jobs and career advancement in health care for recipients of Temporary Assistance for Needy Families (TANF) and other low-income individuals and to respond to the increasing demand for health care professionals. As a demonstration program, HPOG also featured a mandated federal evaluation to assess its success and a corresponding research program—the HPOG University Partnership Research Grants (HPOG UP), a collaborative effort between the program operators and academic researchers from different disciplines—to observe various aspects of its operations. HPOG unites two important innovations in workforce development programming for serving low-income populations in recent decades, career pathways and sector strategies, by actively fostering the use of the former in the context of one major sector—health care. Health care is one of the only sectors that continued to exhibit growth year after year in periods of general economic expansion as well as decline. Health care employment even continued to expand in most states and communities across the United States through the Great Recession in 2008–2009. In addition to offering insights into these strategies and their evolution, the authors in this book present the findings, lessons, and recommendations that emanated from HPOG research and evaluations for consideration by policymakers, program operators, and other researchers.https://research.upjohn.org/up_press/1279/thumbnail.jp

    Strong correlation effects in the doped Hubbard model in infinite dimensions

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    The density of states and the optical conductivity of the doped Hubbard model on a Bethe lattice with infinite connectivities have been studied using an analytic variant of the Lanczos continued fraction method. The spectral weight of the gap states and the position of the chemical potential upon hole or electron doping have been studied. We argue that the strong correlation effects such as gap states and midinfrared band shown in two dimensions also appear in infinite dimensions.Comment: 9 pages, revtex, 3 figures upon reques

    Sub-nanosecond signal propagation in anisotropy engineered nanomagnetic logic chains

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    Energy efficient nanomagnetic logic (NML) computing architectures propagate and process binary information by relying on dipolar field coupling to reorient closely-spaced nanoscale magnets. Signal propagation in nanomagnet chains of various sizes, shapes, and magnetic orientations has been previously characterized by static magnetic imaging experiments with low-speed adiabatic operation; however the mechanisms which determine the final state and their reproducibility over millions of cycles in high-speed operation (sub-ns time scale) have yet to be experimentally investigated. Monitoring NML operation at its ultimate intrinsic speed reveals features undetectable by conventional static imaging including individual nanomagnetic switching events and systematic error nucleation during signal propagation. Here, we present a new study of NML operation in a high speed regime at fast repetition rates. We perform direct imaging of digital signal propagation in permalloy nanomagnet chains with varying degrees of shape-engineered biaxial anisotropy using full-field magnetic soft x-ray transmission microscopy after applying single nanosecond magnetic field pulses. Further, we use time-resolved magnetic photo-emission electron microscopy to evaluate the sub-nanosecond dipolar coupling signal propagation dynamics in optimized chains with 100 ps time resolution as they are cycled with nanosecond field pulses at a rate of 3 MHz. An intrinsic switching time of 100 ps per magnet is observed. These experiments, and accompanying macro-spin and micromagnetic simulations, reveal the underlying physics of NML architectures repetitively operated on nanosecond timescales and identify relevant engineering parameters to optimize performance and reliability.Comment: Main article (22 pages, 4 figures), Supplementary info (11 pages, 5 sections

    Constraint structure of O(3) nonlinear sigma model revisited

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    We study the constraint structure of the O(3) nonlinear sigma model in the framework of the Lagrangian, symplectic, Hamilton-Jacobi as well as the Batalin-Fradkin-Tyutin embedding procedure.Comment: 17 page
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