294 research outputs found
Talking about Public Health: An Analysis of a Municipal Public Health Twitter Feed
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
The final analysis of the experiment determining both components of the
transverse polarization of electrons (, )
emitted in the -decay of polarized, free neutrons is presented. The
T-odd, P-odd correlation coefficient quantifying ,
perpendicular to the neutron polarization and electron momentum, was found to
be 0.0040.005. 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
, 0.0670.004, 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
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
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
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
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
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
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 break-up reaction
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
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
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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