245 research outputs found
Talented suppliers? Strategic change and innovation in the UK aerospace industry
The 1990s marked the start of extensive re-structuring in the aerospace industry throughout the world. While the ensuing consolidation among prime contractors has been widely researched, the changes affecting the aerospace supply chain have received less attention. This study focuses on the re-structuring taking place within the supply chain of the UK aerospace industry. The findings point to extensive re-structuring. Unlike most earlier studies the lean supply model was found to be a powerful influence, with suppliers moving away from subcontractor status and instead taking on the mantle of ‘talented’ suppliers. While some of the implications of lean supply, in terms of the dynamics of innovation, were not apparent, there were modest signs of increased process innovation on the part of some suppliers
Observation of Orbitally Excited B_s Mesons
We report the first observation of two narrow resonances consistent with
states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar
collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the
Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed
as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+,
\bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1})
= 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
Representativeness of aerosol measurements: EARLINET-CALIPSO correlative study
The high variability of tropospheric aerosols, both in
space and time, is the main cause of the high uncertainty
about radiative forcing related to tropospheric aerosols
and their interaction with clouds. Because of the lack of
high resolution aerosol global vertical profiles, the
vertical mixing has not been considered so far in studies
of spatial and temporal variability. The CALIPSO
mission provides the first opportunity to investigate the
4-D aerosol and cloud fields in detail. However, because
of the CALIOP small footprint and the revisit time of 16
days, correlative ground-based lidar observations are
necessary in order to investigate the representativeness
of these satellite observations. EARLINET, the
European Aerosol Research Lidar Network, started
correlative measurements for CALIPSO in June 2006,
right after the CALIPSO launch. An integrated study of
CALIPSO and EARLINET correlative measurements
opens new possibilities for spatial (both horizontal and
vertical) and temporal representativeness investigation
of polar-orbit satellite measurements also in terms of
revisit time.Postprint (published version
Search for chargino-neutralino production in ppbar collisions at sqrt(s) = 1.96 TeV
We present the results of a search for associated production of the chargino
and neutralino supersymmetric particles using up to 1.1 fb-1 of integrated
luminosity collected by the CDF II experiment at the Tevatron ppbar collider at
a center-of-mass energy of 1.96 TeV. The search is conducted by analyzing
events with a large transverse momentum imbalance and either three charged
leptons or two charged leptons of the same electric charge. The numbers of
observed events are found to be consistent with standard model expectations.
Upper limits on the production cross section are derived in different
theoretical models. In one of these models a lower limit on the mass of the
chargino is set at 129 GeV/c^2 at the 95% confidence level.Comment: To be submitted to Phys.Rev.Let
Measurement of the W+W- Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Dilepton Events
We present a measurement of the W+W- production cross section using 184/pb of
ppbar collisions at a center-of-mass energy of 1.96 TeV collected with the
Collider Detector at Fermilab. Using the dilepton decay channel W+W- ->
l+l-vvbar, where the charged leptons can be either electrons or muons, we find
17 candidate events compared to an expected background of 5.0+2.2-0.8 events.
The resulting W+W- production cross section measurement of sigma(ppbar -> W+W-)
= 14.6 +5.8 -5.1 (stat) +1.8 -3.0 (syst) +-0.9 (lum) pb agrees well with the
Standard Model expectation.Comment: 8 pages, 2 figures, 2 tables. To be submitted to Physical Review
Letter
Measurement of the Bs Lifetime in Fully and Partially Reconstructed Bs -> Ds- (phi pi-)X Decays in pbar-p Collisions at sqrt(s) = 1.96 TeV
We present a measurement of the Bs lifetime in fully and partially
reconstructed Bs -> Ds(phi pi)X decays in 1.3 fb-1 of pbar-p collisions at
sqrt(s) = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron.
We measure tau(Bs) = 1.518 +/- 0.041 (stat.) +/- 0.027 (syst.) ps. The ratio of
this result and the world average B0 lifetime yields tau(Bs)/tau(B0) = 0.99
+/-0.03, which is in agreement with recent theoretical predictions.Comment: submitted to Phys. Rev. Let
Observation of the structure in the Mass Spectrum in cays
The observation of the structure in decays produced in collisions at \sqrt{s}=1.96~\TeV is
reported with a statistical significance greater than 5 standard deviations. A
fit to the mass spectrum is performed assuming the presence of a
Breit-Wigner resonance. The fit yields a signal of resonance
events, and resonance mass and width of
4143.4^{+2.9}_{-3.0}(\mathrm{stat})\pm0.6(\mathrm{syst})~\MeVcc and
15.3^{+10.4}_{-6.1}(\mathrm{stat})\pm2.5(\mathrm{syst})~\MeVcc respectively.
The parameters of this resonance-like structure are consistent with values
reported from an earlier CDF analysis.Comment: 7 pages, 2 figures, submited to Phys. Rev. Let
Measurement of the ttbar Production Cross Section in ppbar collisions at sqrt s = 1.96 TeV in the All Hadronic Decay Mode
We report a measurement of the ttbar production cross section using the
CDF-II detector at the Fermilab Tevatron. The analysis is performed using 311
pb-1 of ppbar collisions at sqrt(s)=1.96 TeV. The data consist of events
selected with six or more hadronic jets with additional kinematic requirements.
At least one of these jets must be identified as a b-quark jet by the
reconstruction of a secondary vertex. The cross section is measured to be
sigma(tbart)=7.5+-2.1(stat.)+3.3-2.2(syst.)+0.5-0.4(lumi.) pb, which is
consistent with the standard model prediction.Comment: By CDF collaboratio
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