9,160 research outputs found

    Foreign competition in U.S. banking markets

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    Foreign penetration of U.S. wholesale banking already exceeds that of most other industry groups; unless market capitalization ratios for U.S. banks go up—or down for foreign banks—this trend is likely to continue.Banks and banking, Foreign - United States

    Physics Beyond the Standard Model

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    I present a brief overview of some exciting possibilities for physics Beyond the Standard Model. I include short discussions of neutrino physics, the strong CP problem and axions, GUTs, large and warped extra dimensions, Little Higgs models and supersymmetry. The chances appear excellent that in the next few years-- as the LHC era gets underway-- data from a bevy of experiments will point the way to a new paradigm for the laws of physics as we know them.Comment: 6 pages; to appear in the Proceedings of the Tenth Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2009), San Diego, California, 26-31 May, 200

    Probing Neutralino Resonance Annihilation via Indirect Detection of Dark Matter

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    The lightest neutralino of R-parity conserving supersymmetric models serves as a compelling candidate to account for the presence of cold dark matter in the universe. In the minimal supergravity (mSUGRA) model, a relic density can be found in accord with recent WMAP data for large values of the parameter tanβ\tan\beta, where neutralino annihilation in the early universe occurs via the broad s-channel resonance of the pseudoscalar Higgs boson AA. We map out rates for indirect detection of neutralinos via 1. detection of neutrinos arising from neutralino annihilation in the core of the earth or sun and 2. detection of gamma rays, antiprotons and positrons arising from neutralino annihilation in the galactic halo. If indeed AA-resonance annihilation is the main sink for neutralinos in the early universe, then signals may occur in the gamma ray, antiproton and positron channels, while a signal in the neutrino channel would likely be absent. This is in contrast to the hyperbolic branch/focus point (HB/FP) region where {\it all} indirect detection signals are likely to occur, and also in contrast to the stau co-annihilation region, where {\it none} of the indirect signals are likely to occur.Comment: 12 pages including 4 eps figure

    Digital electronic engine control fault detection and accommodation flight evaluation

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    The capabilities and performance of various fault detection and accommodation (FDA) schemes in existing and projected engine control systems were investigated. Flight tests of the digital electronic engine control (DEEC) in an F-15 aircraft show discrepancies between flight results and predictions based on simulation and altitude testing. The FDA methodology and logic in the DEEC system, and the results of the flight failures which occurred to date are described

    Early search for supersymmetric dark matter models at the LHC without missing energy

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    We investigate early discovery signals for supersymmetry at the Large Hadron Collider without using information about missing transverse energy. Instead we use cuts on the number of jets and isolated leptons (electrons and/or muons). We work with minimal supersymmetric extensions of the standard model, and focus on phenomenological models that give a relic density of dark matter compatible with the WMAP measurements. An important model property for early discovery is the presence of light sleptons, and we find that for an integrated luminosity of only 200--300 pb1^{-1} at a center-of-mass energy of 10 TeV models with gluino masses up to 700\sim 700 GeV can be tested.Comment: 28 pages, 12 figures; published versio

    Supersymmetry Reach of Tevatron Upgrades: The Large tanβ\tan\beta Case

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    The Yukawa couplings of the tau lepton and the bottom quark become comparable to, or even exceed, electroweak gauge couplings for large values of the SUSY parameter tanβ\tan\beta. As a result, the lightest tau slepton \ttau_1 and bottom squark \tb_1 can be significantly lighter than corresponding sleptons and squarks of the first two generations. Gluino, chargino and neutralino decays to third generation particles are significantly enhanced when tanβ\tan\beta is large. This affects projections for collider experiment reach for supersymmetric particles. In this paper, we evaluate the reach of the Fermilab Tevatron ppˉp\bar p collider for supersymmetric signals in the framework of the mSUGRA model. We find that the reach via signatures with multiple isolated leptons (ee and μ\mu) is considerably reduced. For very large tanβ\tan\beta, the greatest reach is attained in the multi-jet+\eslt signature. Some significant extra regions may be probed by requiring the presence of an identified bb-jet in jets+\eslt events, or by requiring one of the identified leptons in clean trilepton events to actually be a hadronic 1 or 3 charged prong tau. In an appendix, we present formulae for chargino, neutralino and gluino three body decays which are valid at large tanβ\tan\beta.Comment: 31 page Revtex file including 10 PS figure

    Mixed axion/neutralino cold dark matter in supersymmetric models

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    We consider supersymmetric (SUSY) models wherein the strong CP problem is solved by the Peccei-Quinn (PQ) mechanism with a concommitant axion/axino supermultiplet. We examine R-parity conserving models where the neutralino is the lightest SUSY particle, so that a mixture of neutralinos and axions serve as cold dark matter. The mixed axion/neutralino CDM scenario can match the measured dark matter abundance for SUSY models which typically give too low a value of the usual thermal neutralino abundance, such as models with wino-like or higgsino-like dark matter. The usual thermal neutralino abundance can be greatly enhanced by the decay of thermally-produced axinos to neutralinos, followed by neutralino re-annihilation at temperatures much lower than freeze-out. In this case, the relic density is usually neutralino dominated, and goes as \sim (f_a/N)/m_{axino}^{3/2}. If axino decay occurs before neutralino freeze-out, then instead the neutralino abundance can be augmented by relic axions to match the measured abundance. Entropy production from late-time axino decays can diminish the axion abundance, but ultimately not the neutralino abundance. In mixed axion/neutralino CDM models, it may be possible to detect both a WIMP and an axion as dark matter relics. We also discuss possible modifications of our results due to production and decay of saxions. In the appendices, we present expressions for the Hubble expansion rate and the axion and neutralino relic densities in radiation, matter and decaying-particle dominated universes.Comment: 31 pages including 21 figure

    Cost-Benefit Analysis of Climate Change: Stern Revisited

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    This paper explores the challenges facing orthodox economic approaches to assessing climate control as if it were appraisal of an investment project. Serious flaws are noted in the work of economists with especial attention to the UK Government report by Stern and colleagues. The opinions expressed in this paper are those of the authors and may not be taken to reflect the views CSIRO or the Australian Government.enhanced greenhouse effect, global CBA, Stern Report

    Hidden SUSY at the LHC: the light higgsino-world scenario and the role of a lepton collider

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    While the SUSY flavor, CP and gravitino problems seem to favor a very heavy spectrum of matter scalars, fine-tuning in the electroweak sector prefers low values of superpotential mass \mu. In the limit of low \mu, the two lightest neutralinos and light chargino are higgsino-like. The light charginos and neutralinos may have large production cross sections at LHC, but since they are nearly mass degenerate, there is only small energy release in three-body sparticle decays. Possible dilepton and trilepton signatures are difficult to observe after mild cuts due to the very soft p_T spectrum of the final state isolated leptons. Thus, the higgsino-world scenario can easily elude standard SUSY searches at the LHC. It should motivate experimental searches to focus on dimuon and trimuon production at the very lowest p_T(\mu) values possible. If the neutralino relic abundance is enhanced via non-standard cosmological dark matter production, then there exist excellent prospects for direct or indirect detection of higgsino-like WIMPs. While the higgsino-world scenario may easily hide from LHC SUSY searches, a linear e^+e^- collider or a muon collider operating in the \sqrt{s}\sim 0.5-1 TeV range would be able to easily access the chargino and neutralino pair production reactions.Comment: 20 pages including 12 .eps figure

    Payments system issues in financial markets that never sleep

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    Payment systems ; Foreign exchange ; Risk ; Stock market
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