2,003 research outputs found
Test Bench Of The Barrel Calorimeter Modules
A systematic procedure to qualify the barrel calorimeter modules is an essential step to guarantee a 0.7% constant term, which is the collaboration objective. The procedure detailed in this note consists of quality monitoring during mechanical assembling and of a set of electrical tests such as electrical continuity, cell and cross-talk capacitance measurement, and high-voltage behaviour. For the whole test, it has been necessary to develop dedicated electronic boards, to develop measurement methods, and the whole operation software. Making the procedure automatic will guarantee the quality of each module during assembling, cabling, and test in liquid argon
Perceived performance of activities of daily living by stroke patients: key in decision to call EMS and outcomes
BackgroundUntil recently, public education campaigns aimed at improving help-seeking behavior by acute stroke patients have achieved only limited or even no effects. Better understanding of psychological factors determining help-seeking behavior may be relevant in the design of more effective future campaigns.MethodsIn this prospective, cross-sectional study, we interviewed 669 acute stroke patients within 72âh after hospital admission. The primary endpoint was the effect of psychological factors on the decision to call emergency medical services (EMS). Secondary endpoints were the effects of such factors on treatment rates and clinical improvement (difference between modified Rankin scale (MRS) scores at admission and at discharge).ResultsOnly 48.7% of the study population called the EMS. Multivariate logistic and linear regression analyses revealed that perception of unimpaired performance of activities of daily living (ADL) was the only psychological factor that predicted EMS use and outcomes. Thus, patients who perceived only minor impairment in performing ADL were less likely to use EMS (odds ratio, 0.54 [95% confidence interval, 0.38â0.76]; pâ=â0.001), had lower treatment rates, and had less improvement in MRS scores (bâ=â0.40, pâ=â0.004). Additional serial mediation analyses involving ischemic stroke patients showed that perception of low impairment in ADL decreased the likelihood of EMS notification, thereby increasing prehospital delays, leading to reduced thrombolysis rates and, finally, to reduced clinical improvement.ConclusionPerception of unimpaired performance of ADL is a crucial barrier to appropriate help-seeking behavior after acute stroke, leading to undertreatment and less improvement in clinical symptoms. Thus, beyond improving the publicâs knowledge of stroke symptoms, future public education campaigns should focus on the need for calling the EMS in case of stroke symptoms even if daily activities do not seem to be severely impaired
Two-Loop Corrections to the Fermionic Decay Rates of the Standard-Model Higgs Boson
Low- and intermediate mass Higgs bosons decay preferably into fermion pairs.
The one-loop electroweak corrections to the respective decay rates are
dominated by a flavour-independent term of . We calculate
the two-loop gluon correction to this term. It turns out that this correction
screens the leading high- behaviour of the one-loop result by roughly
10\%. We also present the two-loop QCD correction to the contribution induced
by a pair of fourth-generation quarks with arbitrary masses. As expected, the
inclusion of the QCD correction considerably reduces the renormalization-scheme
dependence of the prediction.Comment: 14 pages, latex, figures 2-5 appended, DESY 94-08
Energy Linearity and Resolution of the ATLAS Electromagnetic Barrel Calorimeter in an Electron Test-Beam
A module of the ATLAS electromagnetic barrel liquid argon calorimeter was
exposed to the CERN electron test-beam at the H8 beam line upgraded for
precision momentum measurement. The available energies of the electron beam
ranged from 10 to 245 GeV. The electron beam impinged at one point
corresponding to a pseudo-rapidity of eta=0.687 and an azimuthal angle of
phi=0.28 in the ATLAS coordinate system. A detailed study of several effects
biasing the electron energy measurement allowed an energy reconstruction
procedure to be developed that ensures a good linearity and a good resolution.
Use is made of detailed Monte Carlo simulations based on Geant which describe
the longitudinal and transverse shower profiles as well as the energy
distributions. For electron energies between 15 GeV and 180 GeV the deviation
of the measured incident electron energy over the beam energy is within 0.1%.
The systematic uncertainty of the measurement is about 0.1% at low energies and
negligible at high energies. The energy resolution is found to be about 10%
sqrt(E) for the sampling term and about 0.2% for the local constant term
Position resolution and particle identification with the ATLAS EM calorimeter
In the years between 2000 and 2002 several pre-series and series modules of
the ATLAS EM barrel and end-cap calorimeter were exposed to electron, photon
and pion beams. The performance of the calorimeter with respect to its finely
segmented first sampling has been studied. The polar angle resolution has been
found to be in the range 50-60 mrad/sqrt(E (GeV)). The neutral pion rejection
has been measured to be about 3.5 for 90% photon selection efficiency at pT=50
GeV/c. Electron-pion separation studies have indicated that a pion fake rate of
(0.07-0.5)% can be achieved while maintaining 90% electron identification
efficiency for energies up to 40 GeV.Comment: 32 pages, 22 figures, to be published in NIM
Status of the superworld: from theory to experiment
Review to appear in Progress in Particle and Nuclear Physics. Contents:
{1}Introduction}{1} {2}High precision LEP data and convergence of couplings:
physics is not Euclidean geometry}{2} {3}Interconnections between the measured
quantities due to Unification}{7} {4}The origin of and why it should
be abandoned: masses and spectra are needed}{13} {5}The new step forward:
Supergravity}{21} {6}The SU(5) Supergravity Model}{22} {7}SU(5)xU(1)
Supergravity}{32} {8}Detailed calculations for the Tevatron}{47} {9}Detailed
calculations for LEP}{48} {10}Detailed calculations for HERA}{53} {11}Detailed
calculations for Underground Labs and Underwater facilities}{55} {12}Detailed
calculations for indirect experimental detection}{65} {13}The problem of mass
and }{73} {14}Conclusions}{77}Comment: 90 pages, 41 figures (not included), latex. Send requests for hard
copies to "[email protected]". CERN-TH.7136/94, CTP-TAMU-80/9
Search for the glueball candidates f0(1500) and fJ(1710) in gamma gamma collisions
Data taken with the ALEPH detector at LEP1 have been used to search for gamma
gamma production of the glueball candidates f0(1500) and fJ(1710) via their
decay to pi+pi-. No signal is observed and upper limits to the product of gamma
gamma width and pi+pi- branching ratio of the f0(1500) and the fJ(1710) have
been measured to be Gamma_(gamma gamma -> f0(1500)). BR(f0(1500)->pi+pi-) <
0.31 keV and Gamma_(gamma gamma -> fJ(1710)). BR(fJ(1710)->pi+pi-) < 0.55 keV
at 95% confidence level.Comment: 10 pages, 3 figure
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