4,040 research outputs found

    Immersion Research Education: Students as Catalysts for International Collaboration Research

    Get PDF
    Background:  This paper describes an international nursing and health research immersion program. Minority students from the USA work with an international faculty mentor in teams conducting collaborative research. The Minority Health International Research Training (MHIRT) program students become catalysts in the conduct of cross-cultural research. Aim:  To narrow the healthcare gap for disadvantaged families in the USA and partner countries. Methods:  Faculty from the USA, Germany, Italy, Colombia, England, Austria and Thailand formed an international research and education team to explore and compare family health issues, disparities in chronic illness care, social inequities and healthcare solutions. USA students in the MHIRT program complete two introductory courses followed by a 3-month research practicum in a partner country guided by faculty mentors abroad. The overall program development, student study abroad preparation, research project activities, cultural learning, and student and faculty team outcomes are explored. Results:  Cross-fertilization of research, cultural awareness and ideas about improving family health occur through education, international exchange and research immersion. Faculty research and international team collaboration provide opportunities for learning about research, health disparities, cultural influences and healthcare systems. The students are catalysts in the research effort, the dissemination of research findings and other educational endeavours. Five steps of the collaborative activities lead to programmatic success. Conclusions:  MHIRT scholars bring creativity, enthusiasm, and gain a genuine desire to conduct health research about families with chronic illness. Their cultural learning stimulates career plans that include international research and attention to vulnerable populations

    Anisotropic J/ΨJ/\Psi suppression in nuclear collisions

    Full text link
    The nuclear overlap zone in non-central relativistic heavy ion collisions is azimuthally very asymmetric. By varying the angle between the axes of deformation and the transverse direction of the pair momenta, the suppression of J/ΨJ/\Psi and Ψ\Psi' will oscillate in a characteristic way. Whereas the average suppression is mostly sensitive to the early and high density stages of the collision, the amplitude is more sensitive to the late stages. This effect provides additional information on the J/ΨJ/\Psi suppression mechanisms such as direct absorption on participating nucleons, comover absorption or formation of a quark-gluon plasma. The behavior of the average J/ΨJ/\Psi suppression and its amplitude with centrality of the collisions is discussed for SPS, RHIC and LHC energies with and without a phase transition.Comment: Revised and extended version, new figure

    The Origin of Separable States and Separability Criteria from Entanglement-breaking Channels

    Full text link
    In this paper, we show that an arbitrary separable state can be the output of a certain entanglement-breaking channel corresponding exactly to the input of a maximally entangled state. A necessary and sufficient separability criterion and some sufficient separability criteria from entanglement-breaking channels are given.Comment: EBCs with trace-preserving and EBCs without trace-preserving are separately discusse

    Leptoproduction of J/psi

    Full text link
    We study leptoproduction of J/ψJ/\psi at large Q2Q^2 within the nonrelativistic QCD (NRQCD) factorization formalism. The cross section is dominated by color-octet terms that are of order αs\alpha_s. The color-singlet term, which is of order αs2\alpha^2_s, is shown to be a small contribution to the total cross section. We also calculate the tree diagrams for color-octet production at order αs2\alpha^2_s in a region of phase space where there is no leading color-octet contribution. We find that in this regime the color-singlet contribution dominates. We argue that non-perturbative corrections arising from diffractive leptoproduction, higher twist effects, and higher order terms in the NRQCD velocity expansion should be suppressed as Q2Q^2 is increased. Therefore, the color-octet matrix elements and and can be reliably extracted from this process. Finally, we point out that an experimental measurement of the polarization of leptoproduced J/ψJ/\psi will provide an excellent test of the NRQCD factorization formalism.Comment: 33 pages latex. 10 figures. Uses revtex, epsf, and rotate macros. This paper is also available via the UW phenomenology archives at http://phenom.physics.wisc.edu/pub/preprints

    Deep inelastic J/ψJ/\psi production at HERA in the kTk_T-factorization approach and its consequences for the nonrelativistic QCD

    Get PDF
    In the framework of the kTk_T-factorization approach, we analyse the inclusive and inelastic production of J/ψJ/\psi particles in deep inelastic epep scattering. We take into account both colour-singlet and colour-octet production channels. We inspect the sensitivity of theoretical predictions to the choice of model parameters. Our theoretical results agree reasonably well with recent experimental data collected by the collaboration H1 at HERA.Comment: 14 pages, 6 figure

    Search for Chargino-Neutralino Associated Production at the Fermilab Tevatron Collider

    Full text link
    We have searched in ppˉp \bar{p} collisions at s\sqrt{s} = 1.8 TeV for events with three charged leptons and missing transverse energy. In the Minimal Supersymmetric Standard Model, we expect trilepton events from chargino-neutralino (\chione \chitwo) pair production, with subsequent decay into leptons. We observe no candidate e+ee±e^+e^-e^\pm, e+eμ±e^+e^-\mu^\pm, e±μ+μe^\pm\mu^+\mu^- or μ+μμ±\mu^+\mu^-\mu^\pm events in 106 pb1^{-1} integrated luminosity. We present limits on the sum of the branching ratios times cross section for the four channels: \sigma_{\chione\chitwo}\cdot BR(\chione\chitwo\to 3\ell+X) 81.5 \mgev\sp and M_\chitwo > 82.2 \mgev\sp for tanβ=2\tan\beta=2, μ=600\mu =-600~\mgev\sp and M_\squark= M_\gluino.Comment: 9 pages and 3 figure

    Inherent polarization entanglement generated from a monolithic semiconductor chip

    Get PDF
    Creating miniature chip scale implementations of optical quantum information protocols is a dream for many in the quantum optics community. This is largely because of the promise of stability and scalability. Here we present a monolithically integratable chip architecture upon which is built a photonic device primitive called a Bragg reflection waveguide (BRW). Implemented in gallium arsenide, we show that, via the process of spontaneous parametric down conversion, the BRW is capable of directly producing polarization entangled photons without additional path difference compensation, spectral filtering or post-selection. After splitting the twin-photons immediately after they emerge from the chip, we perform a variety of correlation tests on the photon pairs and show non-classical behaviour in their polarization. Combined with the BRW's versatile architecture our results signify the BRW design as a serious contender on which to build large scale implementations of optical quantum processing devices

    Observation of Hadronic W Decays in t-tbar Events with the Collider Detector at Fermilab

    Full text link
    We observe hadronic W decays in t-tbar -> W (-> l nu) + >= 4 jet events using a 109 pb-1 data sample of p-pbar collisions at sqrt{s} = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). A peak in the dijet invariant mass distribution is obtained that is consistent with W decay and inconsistent with the background prediction by 3.3 standard deviations. From this peak we measure the W mass to be 77.2 +- 4.6 (stat+syst) GeV/c^2. This result demonstrates the presence of two W bosons in t-tbar candidates in the W (-> l nu) + >= 4 jet channel.Comment: 20 pages, 4 figures, submitted to PR

    Search for charged Higgs decays of the top quark using hadronic tau decays

    Full text link
    We present the result of a search for charged Higgs decays of the top quark, produced in ppˉp\bar{p} collisions at s=\surd s = 1.8 TeV. When the charged Higgs is heavy and decays to a tau lepton, which subsequently decays hadronically, the resulting events have a unique signature: large missing transverse energy and the low-charged-multiplicity tau. Data collected in the period 1992-1993 at the Collider Detector at Fermilab, corresponding to 18.7±\pm0.7~pb1^{-1}, exclude new regions of combined top quark and charged Higgs mass, in extensions to the standard model with two Higgs doublets.Comment: uuencoded, gzipped tar file of LaTeX and 6 Postscript figures; 11 pp; submitted to Phys. Rev.

    Inclusive jet cross section in pˉp{\bar p p} collisions at s=1.8\sqrt{s}=1.8 TeV

    Full text link
    The inclusive jet differential cross section has been measured for jet transverse energies, ETE_T, from 15 to 440 GeV, in the pseudorapidity region 0.1η\leq | \eta| \leq 0.7. The results are based on 19.5 pb1^{-1} of data collected by the CDF collaboration at the Fermilab Tevatron collider. The data are compared with QCD predictions for various sets of parton distribution functions. The cross section for jets with ET>200E_T>200 GeV is significantly higher than current predictions based on O(αs3\alpha_s^3) perturbative QCD calculations. Various possible explanations for the high-ETE_T excess are discussed.Comment: 8 pages with 2 eps uu-encoded figures Submitted to Physical Review Letter
    corecore