CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2010). Measurement of the Lambda(0)(b) Lifetime in Lambda(0)(b) -> Lambda(+)(c)pi(-) Decays in p(p)over-bar Collisions at root s=1.96 TeV. Phys. Rev. Lett., 104(10), 102002–8pp.
Abstract: We report a measurement of the lifetime of the Lambda(0)(b) baryon in decays to the Lambda(+)(c)pi(-) final state in a sample corresponding to 1.1 fb(-1) collected in p (p) over bar collisions at root s = 1.96 TeV by the CDF II detector at the Tevatron collider. Using a sample of about 3000 fully reconstructed Lambda(0)(b) events we measure tau(Lambda(0)(b) ) = 1.401 +/- 0.046(stat) +/- 0.035(syst) ps (corresponding to c tau(Lambda(0)(b)) = 420.1 +/- 13.7(stat) +/- 10.6(syst) μm, where c is the speed of light). The ratio of this result and the world average B-0 lifetime yields tau(Lambda(0)(b))/tau(B-0) = 0.918 +/- 0.038 (stat) and (syst), in good agreement with recent theoretical predictions.
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CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2010). Measurement of the Ratio sigma(t(t)over-bar)/sigma(Z/gamma*-> ll) and Precise Extraction of the t(t)over-bar Cross Section. Phys. Rev. Lett., 105(1), 012001–7pp.
Abstract: We report a measurement of the ratio of the t (t) over bar to Z/gamma* production cross sections in root s = 1.96 TeV p (p) over bar collisions using data corresponding to an integrated luminosity of up to 4.6 fb(-1), collected by the CDF II detector. The t (t) over bar cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/gamma* -> ll cross section predicted by the standard model, the extracted t (t) over bar cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result sigma(t (t) over bar) = 7.70 +/- 0.52 pb, for a top-quark mass of 172.5 GeV/c(2).
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CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2010). Search for single top quark production in p(p)over-bar collisions at root s=1.96 TeV in the missing transverse energy plus jets topology. Phys. Rev. D, 81(7), 072003–24pp.
Abstract: We report a search for single top quark production with the CDF II detector using 2: 1 fb(-1) of integrated luminosity of p (p) over bar collisions at root s = 1.96 TeV. The data selected consist of events characterized by large energy imbalance in the transverse plane and hadronic jets, and no identified electrons and muons, so the sample is enriched in W -> tau nu decays. In order to suppress backgrounds, additional kinematic and topological requirements are imposed through a neural network, and at least one of the jets must be identified as a b quark jet. We measure an excess of signal-like events in agreement with the standard model prediction, but inconsistent with a model without single top quark production by 2.1 standard deviations (sigma), with a median expected sensitivity of 1.4 sigma. Assuming a top quark mass of 175 GeV/c(2) and ascribing the excess to single top quark production, the cross section is measured to be 4.9(-2.2)(+2.5) (stat + syst) pb, consistent with measurements performed in independent data sets and with the standard model prediction.
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CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2012). Production of Lambda(0), (Lambda)over-bar(0), Xi(+/-), and Omega(+/-) hyperons in p(p)over-bar collisions at root s=1.96 TeV. Phys. Rev. D, 86(1), 012002–10pp.
Abstract: We report a set of measurements of inclusive invariant p(T) differential cross sections of Lambda(0), (Lambda) over bar (0), Xi(+/-), and Omega(+/-) hyperons reconstructed in the central region with pseudorapidity vertical bar eta vertical bar < 1 and p(T) up to 10 GeV/c. Events are collected with a minimum-bias trigger in p<(p)over bar> collisions at a center-of-mass energy of 1.96 TeV using the CDF II detector at the Tevatron Collider. As p(T) increases, the slopes of the differential cross sections of the three particles are similar, which could indicate a universality of the particle production in p(T). The invariant differential cross sections are also presented for different charged-particle multiplicity intervals.
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CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2012). Measurements of the Angular Distributions in the Decays B -> K-(*)mu(+)mu(-) at CDF. Phys. Rev. Lett., 108(8), 081807–8pp.
Abstract: We report an indirect search for nonstandard model physics using the flavor-changing neutral current decays B -> K-(*)mu(+)mu(-). We reconstruct the decays and measure their angular distributions, as a function of q(2) = M(mu mu)(2)c(2), where M-mu μis the dimuon mass, in p (P) over bar collisions at root s = 1.96 Tev using a data sample corresponding to an integrated luminosity of 6.8 fb(-1). The transverse polarization asymmetry A(T)((2)) and the time-reversal-odd charge-and-parity asymmetry A(im) are measured for the first time, together with the K* longitudinal polarization fraction F-L and the muon forward-backward asymmetry A(FB) for the decays B-0 -> K*(0)mu(+)mu(-) and B -> K*(+)mu(+)mu(-). The B -> K*mu(+)mu(-) forward-backward asymmetry in the most sensitive kinematic regime, 1 <= q(2) < 6 GeV2/c(2), is measured to be A(FB) 0.29(-0.23)(+0.20) (stat) +/- 0.07 (syst), the most precise result to date. No deviations from the standard model predictions are observed.
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