23,173 research outputs found

    Search for New Physics at CDF

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    We present the current status of the search for new physics at CDF, using integrated luminosity up to 3.2 fb-1. We cover searches for supersymmetry, extra dimensions, new heavy bosons, and generic dilepton resonances.Comment: Contribution to the proceedings of Lake Louise Winter Institute: Fundamental Interactions (LLWI 2009), Lake Louise, Alberta, Canada, February 16-21, 200

    Search for RS-gravitons at CDF

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    We present a search for Randall-Sundrum (RS) gravitons decaying to diphotons or dielectrons or dimuons, performed with the CDF II detector and using up to 5.7 fb-1 of integrated luminosity. The respective mass spectra are consistent with the ones expected by the standard model. For the RS-model parameter k/M_Pl=0.1, RS-gravitons with mass less than 1111 GeV/c^2 are excluded at 95% CL.Comment: XIX International Workshop on Deep Inelastic Scattering and related subjects -- DIS11, Newport News, VA, USA Apr. 11-15, 2011 [4 pages, 4 figures

    Search for trilepton SUSY signal at CDF

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    The chargino-neutralino production with subsequent leptonic decays is one of the most promising supersymmetry (SUSY) signatures at the Tevatron proton-antiproton collider. We present the most recent results on the search for the three-lepton and missing-transverse-energy SUSY signature using 3.2 fb-1 of data collected with the CDF II detector. The results are interpreted within the minimal supergravity (mSUGRA) scenario.Comment: Proceedings of the 17th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY 09), Boston MA, USA, June 5-10, 2009. To be published by the American Institute of Physic

    Escaping the Large Fine Tuning and Little Hierarchy Problems in the Next to Minimal Supersymmetric Model and h-> aa Decays

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    We demonstrate that the NMSSM can have small fine tuning and modest light stop mass while still evading all experimental constraints. For small tan(beta) [large tan(beta)], the relevant scenarios are such that there is always (often) a SM-like Higgs boson that decays to two lighter -- possibly much lighter -- pseudoscalar Higgses.Comment: 4 pages, 4 figures, revised to conform with PRL published versio

    Many Light Higgs Bosons in the NMSSM

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    The next-to-minimal supersymmetric model with a light doublet-like CP-odd Higgs boson and small tan⁥ÎČ\tan \beta can satisfy all experimental limits on Higgs bosons even with light superpartners. In these scenarios, the two lightest CP-even Higgs bosons, \hi and \hii, and the charged Higgs boson, \hp, can all be light enough to be produced at LEP and yet have decays that have not been looked for or are poorly constrained by existing collider experiments. The channel \hi\to \ai\ai (where \ai is the lightest CP-odd boson and has mass below 2mb2m_b) with \ai\to \tau^+\tau^- or 2j2j is still awaiting LEP constraints for \mhi>86\gev or 82\gev, respectively. LEP data may also contain \epem\to \hii\ai events where \hii\to Z\ai is the dominant decay, a channel that was never examined. Decays of the charged Higgs bosons are often dominated by H^\pm \to W^{\pm (\star)} \ai with \ai \to gg,c \bar c, \tau^+ \tau^-. This is a channel that has so far been ignored in the search for t\to \hp b decays at the Tevatron. A specialized analysis might reveal a signal. The light \ai might be within the reach of BB factories via \Upsilon\to \gamma \ai decays. We study typical mass ranges and branching ratios of Higgs bosons in this scenario and compare these scenarios where the \ai has a large doublet component to the more general scenarios with arbitrary singlet component for the \ai.Comment: 15 pages, 47 figure

    Education and Intergenerational Mobility: Evidence from a Natural Experiment in Purerto Rico

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    The existence of intergenerational spillovers to public investments in schooling is often assumed in policy discussions regarding economic development. However, few studies to date have forwarded convincing evidence that externalities exist for developing countries. In this paper, we address this issue using the arguably exogenous schooling consequences of a major hurricane strike on Puerto Rico in the 1950s. Using data from the US. Census of Population for Puerto Rico, we first find that individuals on to margin of school entry at the time of the storm and residing in the most exposed regions of the island had significantly lower levels of education as adults than their counterparts in less exposed regions. Using the interaction of wind speed and age at the time of the storm as an instrument, we then find that maternal education is related to the probability that a child speaks English. Our estimates imply an additional year of education raise the probability that a child speaks English by between 4.3 and 4.5 percentage points, c approximately 24 to 28 percent. We find no conclusive evidence that parental education increases the probability that a child is enrolled, literate, or in an age-appropriate grad, On balance, these findings suggest that education is responsible at least in part for the persistence of human capital across generations.education, intergenerational mobility, natural experiment, hurricane

    Redox supercapacitor performance of nanocrystalline molybdenum nitrides obtained by ammonolysis of chloride- and amide-derived precursors

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    Reactions of MoCl5 or Mo(NMe2)4 with ammonia result in cubic ?-Mo2N or hexagonal ?1-MoN depending on reaction time and temperature. At moderate temperatures the cubic product from Mo(NMe2)4 exhibits lattice distortions. Fairly high surface areas are observed in the porous particles of the chloride-derived materials and high capacitances of up to 275 F g?1 are observed when electrodes made from them are cycled in aqueous H2SO4 or K2SO4 electrolytes. The cyclic voltammograms suggest charge is largely stored in the electrochemical double layer at the surface of these materials. Amide-derived molybdenum nitrides have relatively low surface areas and smaller capacitances, but do exhibit strong redox features in their cyclic voltammograms, suggesting that redox capacitance is responsible for a significant proportion of the charge stored

    Exploring quark transverse momentum distributions with lattice QCD

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    We discuss in detail a method to study transverse momentum dependent parton distribution functions (TMDs) using lattice QCD. To develop the formalism and to obtain first numerical results, we directly implement a bi-local quark-quark operator connected by a straight Wilson line, allowing us to study T-even, "process-independent" TMDs. Beyond results for x-integrated TMDs and quark densities, we present a study of correlations in x and transverse momentum. Our calculations are based on domain wall valence quark propagators by the LHP collaboration calculated on top of gauge configurations provided by MILC with 2+1 flavors of asqtad-improved staggered sea quarks.Comment: 36 pages, 24 figures; revised version of May 2011, one appendix adde
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