A precise determination of the energy scale of jets at the Collider Detector at Fermilab at the Tevatron
p
p
¯
collider is described. Jets are used in many analyses to estimate the energies of ...partons resulting from the underlying physics process. Several correction factors are developed to estimate the original parton energy from the observed jet energy in the calorimeter. The jet energy response is compared between data and Monte Carlo simulation for various physics processes, and systematic uncertainties on the jet energy scale are determined. For jets with transverse momenta above 50
GeV the jet energy scale is determined with a
3
%
systematic uncertainty.
Intermediate silicon layers detector for the CDF experiment Affolder, A; Azzi-Bacchetta, P; Bacchetta, N ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2000, Letnik:
453, Številka:
1
Journal Article
Recenzirano
The Intermediate Silicon Layers (ISL) detector is currently being built as part of the CDF II detector upgrade project. The ISL detector will significantly improve tracking in the central region and, ...together with the Silicon Vertex detector, provide stand-alone 3D track information in the forward/backward regions. In this article, we present the quality of the production sensors manufactured by Hamamatsu Photonics, which account for roughly half of the silicon sensors used in the ISL detector.
Here, a search for the exotic meson X(5568) decaying into the B$0\atop{s}$π± final state is performed using data corresponding to 9.6 fb-1 from $p\bar{p}$ collisions at $\sqrt{s}$ = 1960 GeV recorded ...by the Collider Detector at Fermilab. No evidence for this state is found and an upper limit of 6.7% at the 95% confidence level is set on the fraction of B$0\atop{s}$ produced through the X(5568)→B$0\atop{s}$π± process.
Status report of the intermediate silicon layers detector at CDFII Affolder, A.; Barbaro-Galtieri, A.; Connolly, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2002, Letnik:
485, Številka:
1
Journal Article
Recenzirano
The
Intermediate Silicon Layers detector (ISL) is a large radius silicon tracker, installed in the CDF detector for the RUN II of the Tevatron Collider. With almost 4
m
2 of double-sided silicon ...sensors and 300,000 electronic channels it represents the biggest system of this kind ever built. The construction and installation phases, the performed quality assurance tests as well as the problems encountered are reviewed.
RUN II of the Tevatron officially started on March 1st, 2001. Although the CDF silicon system is still being commissioned, results on the performance of the ISL detector obtained using the first data are presented.
We present a search for the standard model Higgs boson produced in association with a Z boson, using up to 7.9 fb - 1 of integrated luminosity from p p i?12 collisions collected with the CDF II ...detector. We utilize several novel techniques, including multivariate lepton selection, multivariate trigger parametrization, and a multi-stage signal discriminant consisting of specialized functions trained to distinguish individual backgrounds. By increasing acceptance and enhancing signal discrimination, these techniques have significantly improved the sensitivity of the analysis above what was expected from a larger dataset alone. We observe no significant evidence for a signal, and we set limits on the ZH production cross section. For a Higgs boson with mass 115 GeV / c 2 , we expect (observe) a limit of 3.9 (4.8) times the standard model predicted value, at the 95% credibility level.
Construction report of the intermediate silicon layers (ISL) ladders Affolder, A.; Barbaro-Galtieri, A.; Connolly, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2001, Letnik:
461, Številka:
1
Journal Article
Recenzirano
The Intermediate Silicon Layers (ISL) detector is part of the CDF upgrade for Run II. The ISL is a large radius (20–28
cm) double-side silicon tracker with a total active area of
≃3.5
m
2
. The full ...procedure for module production and electrical tests is described.
We report the most restrictive direct limits on masses of fourth-generation down-type quarks b{prime}, and quark-like composite fermions (B or T{sub 5/3}), decaying promptly to tW{sup {-+}}. We ...search for a significant excess of events with two same-charge leptons (e, {mu}), several hadronic jets, and missing transverse energy. An analysis of data from p{bar p} collisions with an integrated luminosity of 2.7 fb{sup -1} collected with the CDF II detector at Fermilab yields no evidence for such a signal, setting mass limits m{sub b{prime}}, m{sub B} > 338 GeV/c{sup 2} and m{sub T{sub 5/3}} > 365 GeV/c{sup 2} at 95% confidence level.
A search for a narrow Higgs boson resonance in the diphoton mass spectrum is presented based on data corresponding to 7.0 fb^-1 of integrated luminosity from p-pbar collisions at sqrt(s) = 1.96 TeV ...collected by the CDF experiment. No evidence of such a resonance is observed, and upper limits are set on the cross section times branching ratio of the resonant state as a function of Higgs boson mass. The limits are interpreted in the context of the standard model and one fermiophobic benchmark model where the data exclude fermiophobic Higgs bosons with masses below 114 GeV/c^2 at a 95% Bayesian credibility level.
We report the first observation of the baryonic flavor-changing neutral current decay Λb0→Λμ+μ- with 24 signal events and a statistical significance of 5.8 Gaussian standard deviations. This ...measurement uses a pp¯ collisions data sample corresponding to 6.8fb-1 at s=1.96TeV collected by the CDF II detector at the Tevatron collider. The total and differential branching ratios for Λb0→Λμ+μ- are measured. We find B(Λb0→Λμ+μ-)=1.73±0.42(stat)±(syst)×10-6. We also report the first measurement of the differential branching ratio of Bs0→ϕμ+μ-, using 49 signal events. In addition, we report branching ratios for B+→K+μ+μ-, B0→K0μ+μ-, and B→K*(892)μ+μ- decays.
A search has been performed for Bs0→μ+μ- and B0→μ+μ- decays using 7fb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. The observed number of B0 ...candidates is consistent with background-only expectations and yields an upper limit on the branching fraction of B(B0→μ+μ-)<6.0×10-9 at 95% confidence level. We observe an excess of Bs0 candidates. The probability that the background processes alone could produce such an excess or larger is 0.27%. The probability that the combination of background and the expected standard model rate of Bs0→μ+μ- could produce such an excess or larger is 1.9%. These data are used to determine B(Bs0→μ+μ-)=(1.8-0.9+1.1)×10-8 and provide an upper limit of B(Bs0→μ+μ-)<4.0×10-8 at 95% confidence level.