Measurement of the WW and WZ production cross section using final states with a charged lepton and heavy-flavor jets in the full CDF Run II data set

Citation: Aaltonen, T., Amerio, S., Amidei, D., Anastassov, A., Annovi, A., Antos, J., . . . Zucchelli, S. (2016). Measurement of the WW and WZ production cross section using final states with a charged lepton and heavy-flavor jets in the full CDF Run II data set. Physical Review D - Particles, Fields, Gravitation and Cosmology, 94(3). doi:10.1103/PhysRevD.94.032008We present a measurement of the total WW and WZ production cross sections in pp collision at s=1.96 TeV, in a final state consistent with leptonic W boson decay and jets originating from heavy-flavor quarks from either a W or a Z boson decay. This analysis uses the full data set collected with the CDF II detector during Run II of the Tevatron collider, corresponding to an integrated luminosity of 9.4 fb-1. An analysis of the dijet mass spectrum provides 3.7? evidence of the summed production processes of either WW or WZ bosons with a measured total cross section of ?WW+WZ=13.7±3.9 pb. Independent measurements of the WW and WZ production cross sections are allowed by the different heavy-flavor decay patterns of the W and Z bosons and by the analysis of secondary-decay vertices reconstructed within heavy-flavor jets. The productions of WW and of WZ dibosons are independently seen with significances of 2.9? and 2.1?, respectively, with total cross sections of ?WW=9.4±4.2 pb and ?WZ=3.7-2.2+2.5 pb. The measurements are consistent with standard-model predictions. © 2016 American Physical Society

Measurement of sin2 θlept eff using eþe− pairs from γ=Z bosons produced in pp collisions at a center-of-momentum energy of 1.96 TeV

At the Fermilab Tevatron proton-antiproton (pp¯) collider, Drell-Yan lepton pairs are produced in the process pp¯→e+e−+X through an intermediate γ∗/Z boson. The forward-backward asymmetry in the polar-angle distribution of the e− as a function of the e+e−-pair mass is used to obtain sin2θlepteff, the effective leptonic determination of the electroweak-mixing parameter sin2θW. The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to 9.4  fb−1 of integrated luminosity from pp¯ collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of sin2θlepteff is found to be 0.23248±0.00053. The combination with the previous CDF measurement based on μ+μ− pairs yields sin2θlepteff=0.23221±0.00046. This result, when interpreted within the specified context of the standard model assuming sin2θW=1−M2W/M2Z and that the W- and Z-boson masses are on-shell, yields sin2θW=0.22400±0.00045, or equivalently a W-boson mass of 80.328±0.024  GeV/c2

Nonlinear beam self-cleaning in a coupled cavity composite laser based on multimode fiber

We study a coupled cavity laser configuration where a passively Q-switched Nd:YAG microchip laser is combined with an extended cavity, including a doped multimode fiber. For appropriate coupling levels with the extended cavity, we observed that beam selfcleaning was induced in the multimode fiber thanks to nonlinear modal coupling, leading to a quasi-single mode laser output. In the regime of beam self-cleaning, laser pulse duration was reduced from 525 to 225 ps. We also observed a Q-switched mode-locked operation, where spatial self-cleaning was accompanied by far-detuned nonlinear frequency conversion in the active multimode fiber

Study of top quark production and decays involving a tau lepton at CDF and limits on a charged Higgs boson contribution

We present an analysis of top-antitop quark production and decay into a tau lepton, tau neutrino, and bottom quark using data from 9??fb-1 of integrated luminosity at the Collider Detector at Fermilab. Dilepton events, where one lepton is an energetic electron or muon and the other a hadronically decaying tau lepton, originating from proton-antiproton collisions at vs=1.96??TeV, are used. A top-antitop quark production cross section of 8.1±2.1??pb is measured, assuming standard-model top quark decays. By separately identifying for the first time the single-tau and the ditau components, we measure the branching fraction of the top quark into the tau lepton, tau neutrino, and bottom quark to be (9.6±2.8)%. The branching fraction of top quark decays into a charged Higgs boson and a bottom quark, which would imply violation of lepton universality, is limited to be less than 5.9% at a 95% confidence level [for B(H-?t¯?)=1]

Value of intracoronary Doppler for guiding percutaneous interventions

Following the rapid developments in computer software directed towards the anatomical assessment of coronary arteries by quantitative coronary angiography (QCA), interventional cardiologist felt that the anatomical information obtained was sufficient for clinical decision-making. However, further down the line, it became clear that QCA presented some limitations especially in patients with diffuse coronary artery atherosclerosis. In addition, the presence of haziness at the dilated area precluded an accurate estimate of the acute angioplasty results. The latter was further supporter by a lack of correlation observed between the QCA and coronar

AHI1 is required for photoreceptor outer segment development and is a modifier for retinal degeneration in nephronophthisis.

Contains fulltext : 87243.pdf (publisher's version ) (Closed access)Degeneration of photoreceptors is a common feature of ciliopathies, owing to the importance of the specialized ciliary structure of these cells. Mutations in AHI1, which encodes a cilium-localized protein, have been shown to cause a form of Joubert syndrome that is highly penetrant for retinal degeneration. We show that Ahi1-null mice fail to form retinal outer segments and have abnormal distribution of opsin throughout their photoreceptors. Apoptotic cell death of photoreceptors occurs rapidly between 2 and 4 weeks of age in these mice and is significantly (P = 0.00175 and 0.00613) delayed by a reduced dosage of opsin. This phenotype also shows dosage-sensitive genetic interactions with Nphp1, another ciliopathy-related gene. Although it is not a primary cause of retinal blindness in humans, we show that an allele of AHI1 is associated with a more than sevenfold increase in relative risk of retinal degeneration within a cohort of individuals with the hereditary kidney disease nephronophthisis. Our data support context-specific roles for AHI1 as a contributor to retinopathy and show that AHI1 may explain a proportion of the variability in retinal phenotypes observed in nephronophthisis.1 februari 201

Measurement of the top-quark pair production cross-section in events with two leptons and bottom-quark jets using the full CDF data set

We present a measurement of the top-quark pair production cross section in proton-antiproton collisions at s√=1.96  TeV. The data were collected at the Fermilab Tevatron by the CDF II detector and correspond to an integrated luminosity of 8.8  fb−1, representing the complete CDF Run II data set. We select events consistent with the production of top-quark pairs by requiring the presence of two reconstructed leptons, an imbalance in the total event transverse momentum, and jets. At least one jet is required to be identified as consistent with the fragmentation of a bottom quark using a secondary-vertex-finding algorithm. The 246 candidate events are estimated to have a signal purity of 91%. We measure a cross section of σtt¯=7.09±0.84  pb, assuming a top-quark mass of 172.5  GeV/c2. The results are consistent with the standard model as predicted by next-to-leading-order calculations

Combination of searches for the Higgs boson using the full CDF data set

We present a combination of searches for the standard model Higgs boson using the full CDF run II data set, which corresponds to an integrated luminosity of 9.45–10.0  fb−1 collected from s√=1.96  TeV pp¯ collisions at the Fermilab Tevatron. The searches consider Higgs boson production from gluon-gluon fusion, vector-boson fusion, and associated production with either a W or Z boson or a tt¯ pair. Depending on the production mode, Higgs boson decays to W+W−, ZZ, bb¯, τ+τ−, and γγ are examined. We search for a Higgs boson with masses (mH) in the range 90–200  GeV/c2. In the absence of a signal, we expect based on combined search sensitivity to exclude at the 95% credibility level the mass regions 90<mH<94  GeV/c2, 96<mH<106  GeV/c2, and 153<mH<175  GeV/c2. The observed exclusion regions are 90<mH<102  GeV/c2 and 149<mH<172  GeV/c2. A moderate excess of signal-like events relative to the background expectation at the level of 2.0 standard deviations is present in the data for the mH=125  GeV/c2 search hypothesis. We also present interpretations of the data within the context of a fermiophobic model and an alternative standard model incorporating a fourth generation of fermions. Finally, for the hypothesis of a new particle with mass 125  GeV/c2, we constrain the coupling strengths of the new particle to W± bosons, Z bosons, and fermions