993 research outputs found

    Building the foundation for a healthy life: individuals, communities and the state

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    Coherent π^0 photoproduction on the deuteron up to 4 GeV

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    The differential cross section for ^2H(Îł,d)π^0 has been measured at deuteron center-of-mass angles of 90° and 136°. This work reports the first data for this reaction above a photon energy of 1 GeV, and permits a test of the apparent constituent counting rule and reduced nuclear amplitude behavior as observed in elastic ed scattering. Measurements were performed up to a photon energy of 4.0 GeV, and are in good agreement with previous lower energy measurements. Overall, the data are inconsistent with both constituent-counting rule and reduced nuclear amplitude predictions

    Electromagnetic proton form factors in large NcN_{c} QCD

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    The electromagnetic form factors of the proton are obtained using a particular realization of QCD in the large NcN_c limit (QCD∞{QCD}_{\infty}), which sums up the infinite number of zero-width resonances to yield an Euler's Beta function (Dual-QCD∞{QCD}_{\infty}). The form factors F1(q2)F_1(q^2) and F2(q2)F_2(q^2), as well as GM(q2)G_M(q^2) agree very well with reanalyzed space-like data in the whole range of momentum transfer. In addition, the predicted ratio ÎŒpGE/GM\mu_p G_E/G_M is in good agreement with recent polarization transfer measurements at Jefferson Lab.Comment: 10 page

    Can Four Generations Create Harmony Within a Public-Sector Environment?

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    The purpose of this quantitative study was to examine the relationship between generational cohort and cohort perceptions of managerial effectiveness within the context of the federal public service. Data in this study were derived from the Federal Employee Viewpoint Survey, which included 421,748 full-time, part-time, and nonseasonal federal government employees geographically dispersed across the United States and overseas. The results of the study indicated that ratings of managerial effectiveness by all four generational cohorts for all three levels of managers studied were relatively high with correlation coefficients ranging from .96 to .99. However, the only cohort association that consistently had a statistically significant relationship with managerial effectiveness across all three levels was Generation Xers and Millennials. The p value for this relationship was p \u3c .05 for all three managerial levels studied. Based on the study’s data, there was little difference in perceptions regarding managerial effectiveness among the four cohorts. Recommendations for future research include adding perspectives from Generation Z employees who are now entering the federal workforce, and studying how supervisors rate their own supervisors, given their unique managerial experience and perspective within the context of their generational cohort, would add to the body of knowledge on managerial effectiveness among generational cohorts

    Neutron Structure Functions

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    Neutron structure functions can be extracted from proton and deuteron data and a representation of the deuteron structure. This procedure does not require DIS approximations or quark structure assumptions. We find that the results depend critically on properly accounting for the Q^2 dependence of proton and deuteron data. We interpolate the data to fixed Q^2, and extract the ratio of neutron to proton structure functions. The extracted ratio decreases with increasing x, up to x \approx 0.9, while there are no data available to constrain the behavior at larger x.Comment: 16 pages, 6 figure

    Evidence for virtual Compton scattering from the proton

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    In virtual Compton scattering an electron is scattered off a nucleon such that the nucleon emits a photon. We show that these events can be selected experimentally, and present the first evidence for virtual Compton scattering from the proton in data obtained at the Stanford Linear Accelerator Center. The angular and energy dependence of the data is well described by a calculation that includes the coherent sum of electron and proton radiation

    Momentum Transfer Dependence of Nuclear Transparency from the Quasielastic ^(12)C(e, e'p) Reaction

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    The cross section for quasielastic ^(12)C(e,e’p) scattering has been measured at momentum transfer Q^2=1, 3, 5, and 6.8 (GeV/c)^2. The results are consistent with scattering from a single nucleon as the dominant process. The nuclear transparency is obtained and compared with theoretical calculations that incorporate color transparency effects. No significant rise of the transparency with Q^2 is observed

    All electromagnetic form factors

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    The electromagnetic form factors of spin-1/2 particles are known, but due to historical reasons only half of them are found in many textbooks. Given the importance of the general result, its model independence, its connection to discrete symmetries and their violations we made an effort to derive and present the general result based only on the knowledge of Dirac equation. We discuss the phenomenology connected directly with the form factors, and spin precession in external fields including time reversal violating terms. We apply the formalism to spin-flip synchrotron radiation and suggest pedagogical projects.Comment: Latex, 22 page

    Nucleon electromagnetic form factors

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    Elastic electromagnetic nucleon form factors have long provided vital information about the structure and composition of these most basic elements of nuclear physics. The form factors are a measurable and physical manifestation of the nature of the nucleons' constituents and the dynamics that binds them together. Accurate form factor data obtained in recent years using modern experimental facilities has spurred a significant reevaluation of the nucleon and pictures of its structure; e.g., the role of quark orbital angular momentum, the scale at which perturbative QCD effects should become evident, the strangeness content, and meson-cloud effects. We provide a succinct survey of the experimental studies and theoretical interpretation of nucleon electromagnetic form factors.Comment: Topical review invited by Journal of Physics G: Nuclear and Particle Physics; 34 pages (contents listed on page 34), 11 figure

    DonorNet and the Potential Effects on Organ Utilization

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    The evolution of communication as donor data flows from organ procurement organization to transplant centers has evolved with the incorporation of DonorNet 2007 Âź into the UNet SM system. The ensuing study looks at DonorNet's impact on this process. We established defined time periods for comparison purposes. The study looked at match number for organ placement and overall organ utilization with a focus on ischemia time and graft outcomes. The results of the study demonstrate no significant change in the median match number of organ placement in liver or kidney transplantation. Changes in discard rates were varied amongst transplanted organs and there were noticeable changes in organ sharing with an increase in local allocation for kidney and liver and an ensuing decrease in regional and national distribution. There were no significant differences in the outcomes of livers and kidneys with low offer numbers compared with those with high offer numbers. Overall the study suggests a modest impact by DonorNet on organ placement and utilization, but a longer term study would need to be done to fully evaluate its impact.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79141/1/j.1600-6143.2010.03036.x.pd
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