124 research outputs found

    Kaon mixing and the charm mass

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    We study contributions to the Delta S=2 weak Chiral Lagrangian producing K0-K0bar mixing which are not enhanced by the charm mass. For the real part, these contributions turn out to be related to the box diagram with up quarks but, unlike in perturbation theory, they do not vanish in the limit m_u->0. They increase the leading contribution to the K_L-K_S mass difference by ~10%. This means that short distances amount to (90+-15)% of this mass difference. For the imaginary part, we find a correction to the lambda_c^2 m_c^2 term of -5% from the integration of charm, which is a small contribution to epsilon_K. The calculation is done in the large-Nc limit and we show explicitly how to match short and long distances.Comment: 20 pages, 5 figures. Typos fixe

    Smearing Formula for Higher-Order Effective Classical Potentials

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    In the variational approach to quantum statistics, a smearing formula describes efficiently the consequences of quantum fluctuations upon an interaction potential. The result is an effective classical potential from which the partition function can be obtained by a simple integral. In this work, the smearing formula is extended to higher orders in the variational perturbation theory. An application to the singular Coulomb potential exhibits the same fast convergence with increasing orders that has been observed in previous variational perturbation expansions of the anharmonic oscillator with quartic potential.Comment: Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of paper also at http://www.physik.fu-berlin.de/~kleinert/kleiner_re267/preprint.htm

    Off-the-Wall Higgs in the Universal Randall-Sundrum Model

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    We outline a consistent Randall-Sundrum (RS) framework in which a fundamental 5-dimensional Higgs doublet induces electroweak symmetry breaking (EWSB). In this framework of a warped Universal Extra Dimension, the lightest Kaluza-Klein (KK) mode of the bulk Higgs is tachyonic leading to a vacuum expectation value (vev) at the TeV scale. The consistency of this picture imposes a set of constraints on the parameters in the Higgs sector. A novel feature of our scenario is the emergence of an adjustable bulk profile for the Higgs vev. We also find a tower of non-tachyonic Higgs KK modes at the weak scale. We consider an interesting implementation of this ``Off-the-Wall Higgs'' mechanism where the 5-dimensional curvature-scalar coupling alone generates the tachyonic mode responsible for EWSB. In this case, additional relations among the parameters of the Higgs and gravitational sectors are established. We discuss the experimental signatures of the bulk Higgs in general, and those of the ``Gravity-Induced'' EWSB in particular.Comment: 27 pages, 4 figure

    A Self Consistent Reaction Field Calculation of the Fluorobenzonitrile Radical Ions

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    A self consistent reaction field study has been carried out at the MINDO/3 level, in order to explain the decomposition of the species in solution.Publicado on line en 2014.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

    The effects of aging of scientists on their publication and citation patterns

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    The average age at which U.S. researchers get their first grant from NIH has increased from 34.3 in 1970, to 41.7 in 2004. These data raise the crucial question of the effects of aging on the scientific creativity and productivity of researchers. Those who worry about the aging of scientists usually believe that the younger they are the more creative and productive they will be. Using a large population of 13,680 university professors in Quebec, we show that, while scientific productivity rises sharply between 28 and 40, it increases at a slower pace between 41 and 50 and stabilizes afterward until retirement for the most active researchers. The average scientific impact per paper decreases linearly until 50-55 years old, but the average number of papers in highly cited journals and among highly cited papers rises continuously until retirement. Our results clearly show for the first time the natural history of the scientific productivity of scientists over their entire career and bring to light the fact that researchers over 55 still contribute significantly to the scientific community by producing high impact papers.Comment: 12 pages, 4 figure

    Environmental liability litigation could remedy biodiversity loss

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    Abstract: Many countries allow lawsuits to hold responsible parties liable for the environmental harm they cause. Such litigation remains largely untested in most biodiversity hotspots and is rarely used in response to leading drivers of biodiversity loss, including illegal wildlife trade. Yet, liability litigation is a potentially ground‐breaking conservation strategy to remedy harm to biodiversity by seeking legal remedies such as species rehabilitation, public apologies, habitat conservation and education, with the goal of making the injured parties ‘whole’. However, precedent cases, expert guidance, and experience to build such conservation lawsuits is nascent in most countries. We propose a simplified framework for developing conservation lawsuits across countries and conservation contexts. We explain liability litigation in terms of three dimensions: (1) defining the harm that occurred, (2) identifying appropriate remedies to that harm, and (3) understanding what remedies the law and courts will allow. We illustrate the framework via a hypothetical lawsuit against an illegal orangutan trader in Indonesia. We highlight that conservationists’ expertise is essential to characterizing harm and identifying remedies, and could more actively contribute to strategic, science‐based litigation. This would identify priority contexts, target defendants responsible for egregious harm, propose novel and meaningful remedies, and build new transdisciplinary collaborations
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