822 research outputs found
A qualitative assessment of the probability of human exposure to Trichinella spp. in Switzerland
Trichinellosis is a zoonotic disease caused by Trichinella spp. Pork is a potential source of infection for humans. A qualitative assessment was conducted to assess the probability of human exposure to Trichinella spp. in Switzerland via the consumption of pork. For the assessment, both the wildlife cycle and the domestic cycle were taken into account. The probability of occurrence of Trichinella infections in domestic pigs was assessed negligible under controlled housing systems due to biosecurity measures. Free-range pigs were assessed to have a very low probability of being infected. Pork from free-range pigs that were not tested for Trichinella spp. was estimated to carry a very low probability for human exposure to Trichmella spp
The Two Roads to "Intrinsic Charm" in B Decays
We describe two complementary ways to show the presence of higher order
effects in the 1/m_Q expansion for inclusive B decays that have been dubbed
"Intrinsic Charm". Apart from the lessons they can teach us about QCD's
nonperturbative dynamics their consideration is relevant for precise
extractions of |V_{cb}|: for they complement the estimate of the potential
impact of 1/m_Q^4 contributions. We draw semiquantitative conclusions for the
expected scale of Weak Annihilation in semileptonic B decays, both for its
valence and non-valence components.Comment: 17 pages, 3 figure
Development of Readout Interconnections for the Si-W Calorimeter of SiD
The SiD collaboration is developing a Si-W sampling electromagnetic
calorimeter, with anticipated application for the International Linear
Collider. Assembling the modules for such a detector will involve special
bonding technologies for the interconnections, especially for attaching a
silicon detector wafer to a flex cable readout bus. We review the interconnect
technologies involved, including oxidation removal processes, pad surface
preparation, solder ball selection and placement, and bond quality assurance.
Our results show that solder ball bonding is a promising technique for the Si-W
ECAL, and unresolved issues are being addressed.Comment: 8 pages + title, 6 figure
Local Anisotropy of Fluids using Minkowski Tensors
Statistics of the free volume available to individual particles have
previously been studied for simple and complex fluids, granular matter,
amorphous solids, and structural glasses. Minkowski tensors provide a set of
shape measures that are based on strong mathematical theorems and easily
computed for polygonal and polyhedral bodies such as free volume cells (Voronoi
cells). They characterize the local structure beyond the two-point correlation
function and are suitable to define indices of
local anisotropy. Here, we analyze the statistics of Minkowski tensors for
configurations of simple liquid models, including the ideal gas (Poisson point
process), the hard disks and hard spheres ensemble, and the Lennard-Jones
fluid. We show that Minkowski tensors provide a robust characterization of
local anisotropy, which ranges from for vapor
phases to for ordered solids. We find that for fluids,
local anisotropy decreases monotonously with increasing free volume and
randomness of particle positions. Furthermore, the local anisotropy indices
are sensitive to structural transitions in these simple
fluids, as has been previously shown in granular systems for the transition
from loose to jammed bead packs
THGEM-based detectors for sampling elements in DHCAL: laboratory and beam evaluation
We report on the results of an extensive R&D program aimed at the evaluation
of Thick-Gas Electron Multipliers (THGEM) as potential active elements for
Digital Hadron Calorimetry (DHCAL). Results are presented on efficiency, pad
multiplicity and discharge probability of a 10x10 cm2 prototype detector with 1
cm2 readout pads. The detector is comprised of single- or double-THGEM
multipliers coupled to the pad electrode either directly or via a resistive
anode. Investigations employing standard discrete electronics and the KPiX
readout system have been carried out both under laboratory conditions and with
muons and pions at the CERN RD51 test beam. For detectors having a
charge-induction gap, it has been shown that even a ~6 mm thick single-THGEM
detector reached detection efficiencies above 95%, with pad-hit multiplicity of
1.1-1.2 per event; discharge probabilities were of the order of 1e-6 - 1e-5
sparks/trigger, depending on the detector structure and gain. Preliminary beam
tests with a WELL hole-structure, closed by a resistive anode, yielded
discharge probabilities of <2e-6 for an efficiency of ~95%. Methods are
presented to reduce charge-spread and pad multiplicity with resistive anodes.
The new method showed good prospects for further evaluation of very thin
THGEM-based detectors as potential active elements for DHCAL, with competitive
performances, simplicity and robustness. Further developments are in course.Comment: 15 pages, 11 figures, MPGD2011 conference proceedin
Testing the Higgs Mechanism in the Lepton Sector with multi-TeV e+e- Collisions
Multi-TeV e+e- collisions provide with a large enough sample of Higgs bosons
to enable measurements of its suppressed decays. Results of a detailed study of
the determination of the muon Yukawa coupling at 3 TeV, based on full detector
simulation and event reconstruction, are presented. The muon Yukawa coupling
can be determined with a relative accuracy of 0.04 to 0.08 for Higgs bosons
masses from 120 GeV to 150 GeV, with an integrated luminosity of 5 inverse-ab.
The result is not affected by overlapping two-photon background.Comment: 6 pages, 2 figures, submitted to J Phys G.: Nucl. Phy
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