181 research outputs found
Studies of muon-induced radioactivity at NuMI
The JASMIN Collaboration has studied the production of radionuclides by muons
in the muon alcoves of the NuMI beamline at Fermilab. Samples of aluminum and
copper are exposed to the muon field and counted on HpGe detectors when removed
to determine their content of radioactive isotopes. We compare the results to
MARS simulations and discuss the radiological implications for neutrino
factories and muon colliders.Comment: 4 pp. 11th International Workshop on Neutrino Factories, Superbeams
and Betabeams: NuFact 09. 20-25 Jul 2009. Chicago, Illinoi
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Studies of muon-induced radioactivity at NuMI
The JASMIN Collaboration has studied the production of radionuclides by muons in the muon alcoves of the NuMI beamline at Fermilab. Samples of aluminum and copper are exposed to the muon field and counted on HpGe detectors when removed to determine their content of radioactive isotopes. We compare the results to MARS simulations and discuss the radiological implications for neutrino factories and muon colliders
Search for New Physics Using Quaero: A General Interface to D0 Event Data
We describe Quaero, a method that i) enables the automatic optimization of
searches for physics beyond the standard model, and ii) provides a mechanism
for making high energy collider data generally available. We apply Quaero to
searches for standard model WW, ZZ, and ttbar production, and to searches for
these objects produced through a new heavy resonance. Through this interface,
we make three data sets collected by the D0 experiment at sqrt(s)=1.8 TeV
publicly available.Comment: 7 pages, submitted to Physical Review Letter
Schizophrenia and psychotic symptoms in families of two American Indian tribes
Abstract Background The risk of schizophrenia is thought to be higher in population isolates that have recently been exposed to major and accelerated cultural change, accompanied by ensuing socio-environmental stressors/triggers, than in dominant, mainstream societies. We investigated the prevalence and phenomenology of schizophrenia in 329 females and 253 males of a Southwestern American Indian tribe, and in 194 females and 137 males of a Plains American Indian tribe. These tribal groups were evaluated as part of a broader program of gene-environment investigations of alcoholism and other psychiatric disorders. Methods Semi-structured psychiatric interviews were conducted to allow diagnoses utilizing standardized psychiatric diagnostic criteria, and to limit cultural biases. Study participants were recruited from the community on the basis of membership in pedigrees, and not by convenience. After independent raters evaluated the interviews blindly, DSM-III-R diagnoses were assigned by a consensus of experts well-versed in the local cultures. Results Five of the 582 Southwestern American Indian respondents (prevalence = 8.6 per 1000), and one of the 331 interviewed Plains American Indians (prevalence = 3.02 per 1000) had a lifetime diagnosis of schizophrenia. The lifetime prevalence rates of schizophrenia within these two distinct American Indian tribal groups is consistent with lifetime expectancy rates reported for the general United States population and most isolate and homogeneous populations for which prevalence rates of schizophrenia are available. While we were unable to factor in the potential modifying effect that mortality rates of schizophrenia-suffering tribal members may have had on the overall tribal rates, the incidence of schizophrenia among the living was well within the normative range. Conclusion The occurrence of schizophrenia among members of these two tribal population groups is consistent with prevalence rates reported for population isolates and in the general population. Vulnerabilities to early onset alcohol and drug use disorders do not lend convincing support to a diathesis-stressor model with these stressors, commonly reported with these tribes. Nearly one-fifth of the respondents reported experiencing psychotic-like symptoms, reaffirming the need to examine sociocultural factors actively before making positive diagnoses of psychosis or schizophrenia.</p
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A First measurement of the interaction cross-section of the tau neutrino
The DONuT experiment collected data in 1997 and published first results in 2000 based on four observed {nu}{sub {tau}} charged-current (CC) interactions. The final analysis of the data collected in the experiment is presented in this paper, based on 3.6 x 10{sup 17} protons on target using the 800 GeV Tevatron beam at Fermilab. The number of observed {nu}{sub {tau}} CC interactions is 9, from a total of 578 observed neutrino interactions. We calculated the energy-independent part of the tau-neutrino CC cross section ({nu} + {bar {nu}}), relative to the well-known {nu}{sub e} and {nu}{sub {mu}} cross sections. The ratio {sigma}({nu}{sub {tau}})/{sigma}({nu}{sub e,{mu}}) was found to be 1.37 {+-} 0.35 {+-} 0.77. The {nu}{sub {tau}} CC cross section was found to be 0.72 {+-} 0.24 {+-} 0.36 x 10{sup -38} cm{sup 2} GeV{sup -1}. Both results are in agreement with expectations from the Standard Model
Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron
The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is . The combined inclusive and differential asymmetries are consistent with recent standard model predictions
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Production and release of airborne radionuclides due to the operations of NuMI
The operation of the NuMI beamline will result in the production of significant quantities of airborne radionuclides due to the large proton beam intensities to be delivered to this facility. In this report we predict the production of airborne radionuclides and their release to the environment during NuMI operations. An estimate is provided of the maximum dose equivalent that might be delivered by this pathway to a hypothetical individual continuously present at the Fermilab site boundary. Likewise, the dose equivalent rate due to exposure to activated air within the NuMI target station enclosure is estimated. It is concluded that the airborne radioactivity produced in the course of NuMI operations will be in compliance with applicable Federal and State regulations
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