4,176 research outputs found

    General rules for bosonic bunching in multimode interferometers

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    We perform a comprehensive set of experiments that characterize bosonic bunching of up to 3 photons in interferometers of up to 16 modes. Our experiments verify two rules that govern bosonic bunching. The first rule, obtained recently in [1,2], predicts the average behavior of the bunching probability and is known as the bosonic birthday paradox. The second rule is new, and establishes a n!-factor quantum enhancement for the probability that all n bosons bunch in a single output mode, with respect to the case of distinguishable bosons. Besides its fundamental importance in phenomena such as Bose-Einstein condensation, bosonic bunching can be exploited in applications such as linear optical quantum computing and quantum-enhanced metrology.Comment: 6 pages, 4 figures, and supplementary material (4 pages, 1 figure

    Evaluation of the disciplinary competences of the students of the Bachelor's degree in Nursing at 'Sapienza' University of Rome through the TECO: A cross-sectional study

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    The objective of the study is to evaluate whether the TECO-D is a useful tool for measuring the skills acquired by students during three years of the nursing bachelor's degree course at the 'Sapienza' University of Rome. The sample was recruited between January and April 2018. The distribution of the scores for the TECO-D shows an increasing average (standard deviation) from 177.3 ± 28 in the first year up to 214.1 ± 18.5 for graduating students. The test is comprehensive by sampling all relevant disciplines in a curriculum, usually determined by a fixed blueprint. The evaluation of the single macro areas showed statistically significant data reflecting increasing knowledge regarding the progression of the skills. Because of this, we can say that the TECO-D is a great tool for determining student's knowledge in order to evaluate study programs

    eHealth literacy scale: a nursing analysis and Italian validation

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    Background: One of the scales most used to measure quickly and easily eHealth Literacy is the eHealth LiteracyScale (eHEALS); however, there was no validation of this scale in Italian. Therefore, the aim of this study was to adapt and validate the eHealth Literacy Scale (eHEALS) to the italian context. Methods: Italian translation of eHEALS was administered along unit to another two scale for measure lifestyle habits self-esteem and life satisfaction). A sample of 650 university students aged between 18 and 45 years was selected. An exploratory factor analysis, confirmatory factor analysis, analysis of invariance, reliability, stability and bivariate correlations were performed. Results: Exploratory factor analysis revealed a monofactorial structure that explained 67% of variance. Reliability of 0.87 and test-retest correlation of 0.78 was obtained. The questionnaire was invariant by gender. Regarding the criterion validity, a statistically significant and positive correlations between 0.05 and 0.15 with three indicators was obtained (self-esteem, lifestyle habits and life satisfaction). The italian version of the eHEALS tested in this work has shown to be a valid and reliable scale to measure eHealth competence in university students

    L’esperienza dei caregiver primari che assistono a domicilio le persone affette dalla Malattia di Alzheimer [Alzheimer's disease and caregivers experience in home care]

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    The aim of this study is to investigate the experience of primary caregivers (men and women) of Alzheimer Disease dementia, in order to tailor program and project to avoid care giving burden. A qualitative phenomenological method was used and the sample was defined by data saturation. Interviews were carried out and recorded in a day care Centre, transcribed verbatim. The analysis was conducted coding common themes and phrases. Six main themes emerged. Our results are similar to those existing in literature, showing care givers as individual in great danger physically and mentally. In the light of the study it is possible to tailor a nursing model in order to improve quality of life and decrease the burden of caregivers, this model should be implemented and analyzed

    Anisotropic J/ΨJ/\Psi suppression in nuclear collisions

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    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

    Leptoproduction of J/psi

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    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

    Testing Quarkonium Production with Photoproduced J/ψ+γJ/\psi + \gamma

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    I compute the leading color-octet contributions to the process γ+pJ/ψ+γ(+X)\gamma + p \to J/\psi + \gamma (+ X) within the non-relativistic QCD (NRQCD) factorization formalism. In the color-singlet model, J/ψ+γJ/\psi + \gamma can only be produced when the photon interacts through its structure function, while the color-octet mechanism allows for production of J/ψ+γJ/\psi + \gamma via direct photon-gluon fusion. Resolved photon processes can be easily be distinguished from direct photon processes by examining the fraction of the incident photon energy carried away by the J/ψJ/\psi in the event. Therefore, this process provides a conclusive test of the color-octet mechanism. J/ψ+γJ/\psi + \gamma production is particularly sensitive to the NRQCD matrix element which figures prominently in the fragmentation production of J/ψJ/\psi at large pp_{\perp} in hadron colliders. I also examine the predictions of the color evaporation model (CEM) of quarkonium production and find that this process can easily discriminate between the NRQCD factorization formalism and the CEM.Comment: uses Revtex, 12 pages, 4 EPS figures embedded using epsf.sty. Some references have been added. Version accepted for publication in Phys. Rev.
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