391 research outputs found
A High Power Hydrogen Target for Parity Violation Experiments
Parity-violating electron scattering measurements on hydrogen and deuterium,
such as those underway at the Bates and CEBAF laboratories, require
luminosities exceeding cms, resulting in large beam
power deposition into cryogenic liquid. Such targets must be able to absorb 500
watts or more with minimal change in target density. A 40~cm long liquid
hydrogen target, designed to absorb 500~watts of beam power without boiling,
has been developed for the SAMPLE experiment at Bates. In recent tests with
40~A of incident beam, no evidence was seen for density fluctuations in
the target, at a sensitivity level of better than 1\%. A summary of the target
design and operational experience will be presented.Comment: 13 pages, 9 postscript figure
Review from theoretician
The talks presented at the conference are summarized from an angle of a
particle theorist. After presenting a personal impression on the conference,
particular emphasis is placed on the spin structure of nucleons and symmetry
breaking test.Comment: Concluding remark presented at the 7th RCNP International Workshop on
Polarized He Beams and Gas Targets and Their Application, Kobe, Jan.
20-24, 1997, 6 page + 1 Postscript figure, Late
Electroweak Radiative Corrections To Polarized M{\o}ller Scattering Asymmetries
One loop electroweak radiative corrections to left-right parity violating
M{\o}ller scattering () asymmetries are presented. They
reduce the standard model (tree level) prediction by 40 \% where the
main shift and uncertainty stem from hadronic vacuum polarization loops. A
similar reduction also occurs for the electron-electron atomic parity violating
interaction. That effect can be attributed to an increase of
by in running from to 0. The
sensitivity of the asymmetry to ``new physics'' is also discussed.Comment: 14 pages, Revtex, postscript file including figures is available at
ftp://ttpux2.physik.uni-karlsruhe.de/ttp95-14/ttp95-14.ps or via WWW at
http://ttpux2.physik.uni-karlsruhe.de/cgi-bin/preprints/ (129.13.102.139
Three-Nucleon Electroweak Capture Reactions
Recent advances in the study of the p-d radiative and mu-3he weak capture
processes are presented and discussed. The three-nucleon bound and scattering
states are obtained using the correlated-hyperspherical-harmonics method, with
realistic Hamiltonians consisting of the Argonne v14 or Argonne v18 two-nucleon
and Tucson-Melbourne or Urbana IX three-nucleon interactions. The
electromagnetic and weak transition operators include one- and two-body
contributions. The theoretical accuracy achieved in these calculations allows
for interesting comparisons with experimental data.Comment: 12 pages, 4 figures, invited talk at the CFIF Fall Workshop: Nuclear
Dynamics, from Quarks to Nuclei, Lisbon, 31st of October - 1st of November
200
Tried and true: A survey of successfully promoted academic hospitalists
BACKGROUND: Academic hospital medicine is a new and rapidly growing field. Hospitalist faculty members often fill roles not typically held by other academic faculty, maintain heavy clinical workloads, and participate in nontraditional activities. Because of these differences, there is concern about how academic hospitalists may fare in the promotions process. OBJECTIVE: To determine factors critical to the promotion of successfully promoted hospitalists who have achieved the rank of either associate professor or professor. DESIGN: A crossâsectional survey. PARTICIPANTS: Thirtyâthree hospitalist faculty members at 22 academic medical centers promoted to associate professor rank or higher between 1995 and 2008. MEASUREMENTS: Respondents were asked to describe their institution, its promotions process, and the activities contributing to their promotion. We identified trends across respondents. RESULTS: Twentyâsix hospitalists responded, representing 20 institutions (79% response rate). Most achieved promotion in a nontenure track (70%); an equal number identified themselves as clinicianâadministrators and clinician educators (40%). While hospitalists were engaged in a wide range of activities in the traditional domains of service, education, and research, respondents considered peerâreviewed publication to be the most important activity in achieving promotion. Qualitative responses demonstrated little evidence that being a hospitalist was viewed as a hindrance to promotion. CONCLUSIONS: Successful promotion in academic hospital medicine depends on accomplishment in traditional academic domains, raising potential concerns for academic hospitalists with less traditional roles. This study may provide guidance for earlyâcareer academic hospitalists and program leaders. Journal of Hospital Medicine 2011. © 2011 Society of Hospital MedicinePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86910/1/894_ftp.pd
Deuteron Electroweak Disintegration
We study the deuteron electrodisintegration with inclusion of the neutral
currents focusing on the helicity asymmetry of the exclusive cross section in
coplanar geometry. We stress that a measurement of this asymmetry in the quasi
elastic region is of interest for an experimental determination of the weak
form factors of the nucleon, allowing one to obtain the parity violating
electron neutron asymmetry. Numerically, we consider the reaction at low
momentum transfer and discuss the sensitivity of the helicity asymmetry to the
strangeness radius and magnetic moment. The problems coming from the finite
angular acceptance of the spectrometers are also considered.Comment: 30 pages, Latex, 7 eps figures, submitted to Phys.Rev.C e-mail:
[email protected] , [email protected]
Observation of Parity Nonconservation in Moller Scattering
We report a measurement of the parity-violating asymmetry in fixed target
electron-electron (Moller) scattering: A_PV = -175 +/- 30 (stat.) +/- 20
(syst.) parts per billion. This first direct observation of parity
nonconservation in Moller scattering leads to a measurement of the electron's
weak charge at low energy Q^e_W = -0.053 +/- 0.011. This is consistent with the
Standard Model expectation at the current level of precision:
sin^2\theta_W(M_Z)_MSbar = 0.2293 +/- 0.0024 (stat.) +/- 0.0016 (syst.) +/-
0.0006 (theory).Comment: Version 3 is the same as version 2. These versions contain minor text
changes from referee comments and a change in the extracted value of Q^e_W
and sin^2\theta_W due to a change in the theoretical calculation of the
bremsstrahulung correction (ref. 16
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