8 research outputs found
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
Search for Anomalous Production of Events with Two Photons and Additional Energetic Objects at CDF
submitted to Phys. Rev. DInternational audienceWe present results of a search for anomalous production of two photons together with an electron, muon, lepton, missing transverse energy, or jets using collision data from 1.1-2.0 fb of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs of new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis techniques that significantly reduce instrumental backgrounds in channels with an electron and missing transverse energy
Search for Technicolor Particles Produced in Association with a W Boson at CDF
submitted to Phys. Rev. LettInternational audienceWe present a search for the technicolor particles and in the process at a center of mass energy of . The search uses a data sample corresponding to approximately of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is and or depending on the charge. We select events with a single high- electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple -tagging algorithms. The observed number of events and the invariant mass distributions are consistent with the standard model background expectations, and we exclude a region at 95% confidence level in the - mass plane. As a result, a large fraction of the region - and - is excluded
Measurement of Z gamma Production in pbar{p} Collisions at sqrt{s} = 1.96 TeV
8 pages, 3 figures, Submitted to PRDThe production rate and kinematics of photons produced in association with Z bosons are studied using 2/fb of p\bar{p} collision data collected at the Collider Detector at Fermilab. The cross section for p\bar{p} -> l^+ l^- gamma + X (where the leptons l are either muons or electrons with dilepton mass M_{ll} > 40 GeV/c^2, and where the photon has transverse energy Et_{gamma} > 7 GeV and is well separated from the leptons) is 4.6 +/- 0.2 (stat) +/- 0.3 (syst) +/- 0.3 (lum) pb, which is consistent with standard model expectations. We use the photon Et distribution from Z-gamma events where the Z has decayed to mu^+ mu^-, e^+ e^-, or nu\bar{nu} to set limits on anomalous (non-standard-model) trilinear couplings between photons and Z bosons
Causes of preventable drug-related hospital admissions: a qualitative study
Objective: To explore the causes of preventable drug-related admissions (PDRAs) to hospital. Design: Qualitative case studies using semi-structured interviews and medical record review; data analysed using a framework derived from Reason's model of organisational accidents and cascade analysis. Participants: 62 participants, including 18 patients, 8 informal carers, 17 general practitioners, 12 community pharmacists, 3 practice nurses and 4 other members of healthcare staff, involved in events leading up to the patients' hospital admissions. Setting: Nottingham, UK. Results: PDRAs are associated with problems at multiple stages in the medication use process, including prescribing, dispensing, administration, monitoring and help seeking. The main causes of these problems are communication failures ( between patients and healthcare professionals and different groups of healthcare professionals) and knowledge gaps ( about drugs and patients' medical and medication histories). The causes of PDRAs are similar irrespective of whether the hospital admission is associated with a prescribing, monitoring or patient adherence problem. Conclusions: The causes of PDRAs are multifaceted and complex. Technical solutions to PDRAs will need to take account of this complexity and are unlikely to be sufficient on their own. Interventions targeting the human causes of PDRAs are also necessary - for example, improving methods of communication
Autoridades interpretativas: una perspectiva teórica sobre datificación y producción de sentido
Este artículo emerge en el espacio de contacto entre la literatura actual –de corte mayormente
anglosajón– sobre datificación, y la perspectiva de Eliseo Verón como un aporte
latinoamericano que abre oportunidades teóricas y empíricas para la discusión crítica de los
procesos de datificación.
Siguiendo la perspectiva de veroniana, la reflexión sobre los procesos de producción,
circulación, y reconocimiento de los datos ayuda a desnaturalizar la idea de que el dato es
neutral o compacto, para visibilizar, en cambio, las condiciones desde las que esos datos son
provistos de sentido en tanto que constructos discursivos social y culturalmente situados.
Frente a otras perspectivas anglosajonas que parecen más populares en la academia –i.e., el
modelo Encoding/decoding de Hall–, este artículo propone revisitar la descripción de la
articulación entre sentido y circulación por parte de Verón como una alternativa para
describir los procesos de interpretación que consolidan los datos como discursos. Se trata,
pues, de un punto de partida para posteriores desarrollos teóricos e investigaciones empíricas,y de una apertura de la perspectiva de Eliseo Verón para contribuir y enriquecer los debates
abiertos sobre datificación y sus formas de discriminación
Invariant Mass Distribution of Jet Pairs Produced in Association with a W Boson in pp̅ Collisions at √s=1.96 TeV
We report a study of the invariant mass distribution of jet pairs produced in association with a W boson using data collected with the CDF detector which correspond to an integrated luminosity of 4.3 fb[superscript -1]. The observed distribution has an excess in the 120–160 GeV/c[superscript 2] mass range which is not described by current theoretical predictions within the statistical and systematic uncertainties. In this Letter, we report studies of the properties of this excess.National Science Foundation (U.S.)United States. Dept. of EnergyAlfred P. Sloan Foundatio