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 Y(4140)Y(4140) structure in the J/ψ ϕJ/\psi\,\phi Mass Spectrum in B±→J/ψ ϕKB^\pm\to J/\psi\,\phi K cays

The observation of the $Y(4140)$ structure in $B^\pm\rightarrow J/\psi\,\phi K^\pm$ decays produced in $\bar{p} p$ collisions at \sqrt{s}=1.96~\TeV is reported with a statistical significance greater than 5 standard deviations. A fit to the $J/\psi\,\phi$ mass spectrum is performed assuming the presence of a Breit-Wigner resonance. The fit yields a signal of $19^{+6}_{-5}$ 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

Combination of CDF and D0 results on the W boson mass and width

The results based on 1992–95 data (Run 1) from the CDF and D0 experiments on the measurements of the W boson mass and width are presented, along with the combined results. We report a Tevatron collider average MW=80.456±0.059  GeV. We also report the Tevatron collider average of the directly measured W boson width ΓW=2.115±0.105  GeV. We describe a new joint analysis of the direct W mass and width measurements. Assuming the validity of the standard model, we combine the directly measured W boson width with the width extracted from the ratio of W and Z boson leptonic partial cross sections. This combined result for the Tevatron is ΓW=2.135±0.050  GeV. Finally, we use the measurements of the direct total W width and the leptonic branching ratio to extract the leptonic partial width Γ(W→eν)=224±13  MeV

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, $\tau$ lepton, missing transverse energy, or jets using $p\bar{p}$ collision data from 1.1-2.0 fb$^{-1}$ 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

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

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 $\rho_{T}$ and $\pi_{T}$ in the process $p\bar{p} \to \rho_{T} \to W\pi_{T}$ at a center of mass energy of $\sqrt{s}=1.96 \mathrm{TeV}$. The search uses a data sample corresponding to approximately $1.9 \mathrm{fb}^{-1}$ of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is $W\to \ell\nu$ and $\pi_{T} \to b\bar{b}, b\bar{c}$ or $b\bar{u}$ depending on the $\pi_{T}$ charge. We select events with a single high-$p_T$ electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple $b$-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 $\rho_T$-$\pi_T$ mass plane. As a result, a large fraction of the region $m(\rho_T) = 180$ - $250 \mathrm{GeV}/c^2$ and $m(\pi_T) = 95$ - $145 \mathrm{GeV}/c^2$ 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