294 research outputs found

    Talking about Public Health: An Analysis of a Municipal Public Health Twitter Feed

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    Social media has become an increasingly popular tool used by experts and laypeople alike to obtain, share, and create health information. Public health authorities have also begun to use web 2.0 platforms to share information and foster engagement with the public. Existing public health research about Twitter has explored its uses as a tool of health promotion, however communication on the Twitter platform has not yet been explored from a critical public health perspective. The purpose of this study is to analyze how talk about public health occurs online via Twitter. Using both content and discourse analysis of communication on Toronto Public Health\u27s official Twitter feed, this study explores emergent themes of biomedicalization; how biomedical power is affirmed; and assesses whether Twitter can be a useful platform to facilitate a dialogue between citizen and state. The immediacy and transparency, characteristic of the Twitter platform, do support dialogues that question and responsibilize the health authority, however biomedical power is most often affirmed rather than challenged. This study argues that while Twitter may be an effective tool to facilitate engagement, it does little to reshape the existing power dynamic between citizen and state

    Measurement of Transverse Polarization of Electrons Emitted in Free Neutron Decay

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    The final analysis of the experiment determining both components of the transverse polarization of electrons (σT1\sigma_{T_{1}}, σT2\sigma_{T_{2}}) emitted in the β\beta-decay of polarized, free neutrons is presented. The T-odd, P-odd correlation coefficient quantifying σT2\sigma_{T_{2}}, perpendicular to the neutron polarization and electron momentum, was found to be R=R= 0.004±0.012±\pm0.012\pm0.005. This value is consistent with time reversal invariance, and significantly improves both earlier result and limits on the relative strength of imaginary scalar couplings in the weak interaction. The value obtained for the correlation coefficient associated with σT1\sigma_{T_{1}}, N=N= 0.067±0.011±\pm0.011\pm0.004, agrees with the Standard Model expectation, providing an important sensitivity test of the experimental setup. The present result sets constraints on the imaginary part of scalar and tensor couplings in weak interaction. Implications for parameters of the leptoquark exchange model and minimal supersymmetric model (MSSM) with R-parity violation are discussed

    Study of three-nucleon dynamics in the dp breakup collisions using the Wasa detector

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    An experiment to investigate the ^{1}H(d,pp)n breakup reaction using a deuteron beam of 300, 340, 380 and 400 MeV and the WASA detector has been performed at the Cooler Synchrotron COSY-Jülich. As a first step, the data collected at the beam energy of 340 MeV are analysed, with a focus on the proton–proton coincidences registered in the Forward Detector. Elastically scattered deuterons are used for precise determination of the luminosity. The main steps of the analysis, including energy calibration, particle identification (PID) and efficiency studies, and their impact on the final accuracy of the result, are discussed

    Study of three-nucleon dynamics in the dp breakup collisions using the Wasa detector

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    An experiment to investigate the ^{1}H(d,pp)n breakup reaction using a deuteron beam of 300, 340, 380 and 400 MeV and the WASA detector has been performed at the Cooler Synchrotron COSY-Jülich. As a first step, the data collected at the beam energy of 340 MeV are analysed, with a focus on the proton–proton coincidences registered in the Forward Detector. Elastically scattered deuterons are used for precise determination of the luminosity. The main steps of the analysis, including energy calibration, particle identification (PID) and efficiency studies, and their impact on the final accuracy of the result, are discussed

    Dynamical effects in invariant coordinates for dp breakup

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    Regular studies of few-nucleon systems reveal various dynamical components, such as three-nucleon force, Coulomb force and relativistic effects, which play an important role in correct description of nuclear interaction. A large set of existing experimental data for 1H(d; pp)n reaction allows for systematic investigations of these dynamical effects, which vary with energy and appear with different strength in certain observables and phase space regions. In order to perform systematic comparisons with precise theoretical calculations, the experimental data are transformed to the variables based on the Lorentz invariants

    Measurement of the Transverse Polarization of Electrons Emitted in Free Neutron Decay

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    Both components of the transverse polarization of electrons emitted in the beta-decay of polarized, free neutrons have been measured. The T-odd, P-odd correlation coefficient quantifying the component perpendicular to the decay plane defined by neutron polarization and electron momentum, was found to be R=0.008 +/- 0.015 +/-0.005. This value is consistent with time reversal invariance, and significantly improves limits on the relative strength of imaginary scalar couplings in the weak interaction. The value obtained for the correlation coefficient associated with the electron polarization component contained within the decay plane N=0.056 +/- 0.011 +/- 0.005, agrees with the Standard Model expectation, providing an important sensitivity test of the experimental setup.Comment: 4 pages, 4 figure

    Probing three- and four-nucleon interactions with the deuteron breakup reaction

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    Research in the domain of few-nucleon systems concerns reactions involving a small number of nucleons in which observables can be compared directly to exact computational methods — rigorous solutions of the Faddeev equations. The investigations of such systems reveal existence of various dynamical ingredients such as the three-nucleon force, the Coulomb force or relativistic effects. A large set of the cross-section data of the ^{1}H(d,pp)n breakup reaction obtained at energy of 130 MeV was used to trace the Coulomb force effects. Comparisons of the cross-section data with the predictions using the realistic Argonne 18 potential are presented. The new set of invariants was introduced to describe the process with three nucleons in the final state

    The Quest for New Data on the Space Star Anomaly in Pd Breakup

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    Even though the development of the theories providing a precise description of few-nucleon interactions is well advanced, certain inconsistencies between experimental data and theoretical predictions are still to be resolved, one of which is the Space Star Anomaly in deuteron-proton breakup. As the cross-sections for the star configurations are measured mainly for the energy range below 20 MeV, new measurements at higher energies could give an important hint for a possible source of the discrepancy between experimental data and the theoretical predictions. In this contribution, the very first preliminary 160 MeV deuteron on proton p(d, pp)n breakup cross-sections for the star configuration measured with the BINA experimental setup are presented.</p

    Measurements of scattering observables for the pdpd break-up reaction

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    High-precision measurements of the scattering observables such as cross sections and analyzing powers for the proton-deuteron elastic and break-up reactions have been performed at KVI in the last two decades and elsewhere to investigate various aspects of the three-nucleon force (3NF) effects simultaneously. In 2006 an experiment was performed to study these effects in p+d\vec{p}+d break-up reaction at 135 MeV with the detection system, Big Instrument for Nuclear polarization Analysis, BINA. BINA covers almost the entire kinematical phase space of the break-up reaction. The results are interpreted with the help of state-of-the-art Faddeev calculations and are partly presented in this contribution.Comment: Proceedings of 19th International IUPAP Conference on Few-Body Problems in Physics, Bonn University, 31.08 - 05.09.2009, Bonn, GERMAN

    Experimental study of three-nucleon dynamics in proton-deuteron breakup reaction

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    Proton–deuteron breakup reaction can serve as a tool to test stateof- the-art descriptions of nuclear interactions. At intermediate energies, below the threshold for pion production, comparison of the data with exact theoretical calculations is possible and subtle effects of the dynamics beyond the pairwise nucleon–nucleon interaction, namely the three-nucleon force (3NF), are significant. Beside 3NF, Coulomb interaction or relativistic effects are also important to precisely describe the differential cross section of the breakup reaction. The data analysis and preliminary results of the measurement of proton-induced deuteron breakup at the Cyclotron Center Bronowice, Institute of Nuclear Physics, Polish Academy of Sciences in Kraków are presented
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