6,187 research outputs found
Choice and the composition of general practice patient registers
Choice of general practice (GP) in the National Health Service (NHS), the UKs universal healthcare
service, is a core element in the current trajectory of NHS policy. This paper uses an accessibility-based
approach to investigate the pattern of patient choice that exists for GPs in the London
Borough of Southwark. Using a spatial model of GP accessibility it is shown that particular population
groups make non-accessibility based decisions when choosing a GP. These patterns are assessed by
considering differences in the composition of GP patient registers between the current patient
register, and a modelled patient register configured for optimal access to GPs. The patient
population is classified in two ways for the purpose of this analysis: by geodemographic group, and
by ethnicity. The paper considers choice in healthcare for intra-urban areas, focusing on the role of
accessibility and equity
Measurement of the Υ (1S) production cross-section in pp collisions at √s = 7 TeV in ATLAS
A measurement of the cross-section for Υ (1S)→μ^+μ^− production in proton–proton collisions at centre of mass energy of 7 TeV is presented. The cross-section is measured as a function of the Υ (1S) transverse momentum in two bins of rapidity, |y^(Υ(1S))| 4 GeV and pseudorapidity |η^μ| < 2.5 in order to reduce theoretical uncertainties on the acceptance, which depend on the poorly known polarisation. The results are based on an integrated luminosity of 1.13 pb^(−1), collected with the ATLAS detector at the
Large Hadron Collider. The cross-section measurement is compared to theoretical predictions: it agrees
to within a factor of two with a prediction based on the NRQCD model including colour-singlet and
colour-octet matrix elements as implemented in Pythia while it disagrees by up to a factor of ten with
the next-to-leading order prediction based on the colour-singlet model
Search for pair production of first or second generation leptoquarks in proton-proton collisions at √s = 7 TeV using the ATLAS detector at the LHC
This paper describes searches for the pair production of first or second generation scalar leptoquarks using 35 pb^(-1) of proton-proton collision data recorded by the ATLAS detector at √s=7 TeV. Leptoquarks are searched in events with two oppositely-charged muons or electrons and at least two jets, and in events with one muon or electron, missing transverse momentum and at least two jets. After event selection, the observed yields are consistent with the predicted backgrounds. Leptoquark production is excluded at the 95% CL for masses M_(LQ)<376 (319) GeV and M_(LQ)<422 (362) GeV for first and second generation scalar leptoquarks, respectively, when assuming the branching fraction of a leptoquark to a charged lepton is equal to 1.0 (0.5)
Limits on the production of the standard model Higgs boson in pp collisions at √s = 7 TeV with the ATLAS detector
A search for the Standard Model Higgs boson at the Large Hadron Collider (LHC) running at a centre-of-mass energy of 7 TeV is reported, based on a total integrated luminosity of up to 40 pb^(−1) collected by the ATLAS detector in 2010. Several Higgs boson decay channels: H→γγ, H→ZZ^((∗))→ℓℓℓℓ, H→ZZ→ℓℓνν, H→ZZ→ℓℓqq, H→WW^((∗))→ℓνℓν and H→WW→ℓνqq (ℓ is e, μ) are combined in a mass range from 110 GeV to 600 GeV. The highest sensitivity is achieved in the mass range between 160 GeV and 170 GeV, where the expected 95% CL exclusion sensitivity is at Higgs boson production cross sections 2.3 times the Standard Model prediction. Upper limits on the cross section for its production are determined. Models with a fourth generation of heavy leptons and quarks with Standard Model-like couplings to the Higgs boson are also investigated and are excluded at 95% CL for a Higgs boson mass in the range from 140 GeV to 185 GeV
In-situ Determination of the ATLAS Muon Performance
The ATLAS detector allows for the precise and efficient reconstruction of muons. Muon
tracks are reconstructed with 97% efficiency with a momentum resolution of approximately 2-3%
over most of the kinematic range and better than 10% for transverse momenta up to 1 TeV and
|η| <2.7. We present methods to measure the performance of the muon identification during the
operation of the ATLAS detector using muons from Z and J/ψdecays
Measurement of the W charge asymmetry in the W→μν decay mode in pp collisions at √s = 7 TeV with the ATLAS detector
This Letter reports a measurement of the muon charge asymmetry from W bosons produced in proton–proton collisions at a centre-of-mass energy of 7 TeV with the ATLAS experiment at the LHC. The asymmetry is measured in the W→μν decay mode as a function of the muon pseudorapidity using a data sample corresponding to a total integrated luminosity of 31 pb^(−1). The results are compared to predictions based on next-to-leading order calculations with various parton distribution functions. This measurement provides information on the u and d quark momentum fractions in the proton
Search for Diphoton Events with Large Missing Transverse Energy in 7 TeV Proton-Proton Collisions with the ATLAS Detector
A search for diphoton events with large missing transverse energy is presented. The data were collected with the ATLAS detector in proton-proton collisions at √s = 7 TeV at the CERN Large Hadron Collider and correspond to an integrated luminosity of 3.1 pb^(-1). No excess of such events is observed above the standard model background prediction. In the context of a specific model with one universal extra dimension with compactification radius R and gravity-induced decays, values of 1/R < 729 GeV are excluded at 95% C.L., providing the most sensitive limit on this model to date
A search for new physics in dijet mass and angular distributions in pp collisions at √s = 7 TeV measured with the ATLAS detector
A search for new interactions and resonances produced in LHC proton–proton (pp) collisions at a centre-of-mass energy √s = 7 TeV was performed with the ATLAS detector. Using a dataset with an integrated luminosity of 36 pb^(−1), dijet mass and angular distributions were measured up to dijet masses of ~3.5 TeV and were found to be in good agreement with Standard Model predictions. This analysis sets limits at 95% CL on various models for new physics: an excited quark is excluded for mass between 0.60 and 2.64 TeV, an axigluon hypothesis is excluded for axigluon masses between 0.60 and 2.10 TeV and quantum black holes are excluded in models with six extra space–time dimensions for quantum gravity scales between 0.75 and 3.67 TeV. Production cross section limits as a function of dijet mass are set using a simplified Gaussian signal model to facilitate comparisons with other hypotheses. Analysis of the dijet angular distribution using a novel technique simultaneously employing the dijet mass excludes quark contact interactions with a compositeness scale Λ below 9.5 TeV
Soliton fermionic number from the heat kernel expansion
Producción CientíficaWe consider different methods of calculating the (fractional) fermion number of solitons based on the heat kernel expansion. We derive a formula for the localized η function that provides a more systematic version of the derivative expansion for spectral asymmetry and compute the fermion number in amulti flavor extension of the Goldstone–Wilczek model. We also propose an improved expansion of the heat
kernel that allows the tackling of the convergence issues and permits an automated computation of the coefficients.Juant de Castilla y León grant BU 229P18
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