Narrow Results

In the proton–antiproton collisions at Fermilab, individual top quarks are expected to be produced by an electroweak mechanism referred to as single-top-quark production. In this paper we review the CDF results of the search for single-top-quarks, along with the prospects for the current collider run.

We discuss recent B physics results from the DØ experiment at Fermilab. The results presented here use data sets with integrated luminosities ranging from ~ 200–440 pb^-1, collected at the Tevatron, between April 2002 and August 2004, at a center-of-mass energy of collisions of 1.96 TeV.

We present a review of searches for electroweak production of single top quarks at the Fermilab Tevatron proton–antiproton collider at . Searches for s-channel and t-channel single top quark production have been carried out using secondary-vertex b-quark tagging and advanced event analysis methods in order to maximize the sensitivity to single top quark production. So far, no evidence for a single top quark signal has been found. However, 95% confidence level upper limits on the production cross-section have been set that improve upon previous limits by factors of two to three and are approaching the cross-section region predicted by the standard model.

The search for neutral resonances at the energy frontier has a long and illustrious history, resulting in multiple discoveries. The canonical search scans the reconstructed invariant mass distribution of identified fermion pairs. Two recent analyses from the CDF experiment at the Fermilab Tevatron have applied novel methods to resonance searches. One analysis uses simulated templates to fit the inverse mass distribution of muon pairs, a quantity with approximately constant resolution for momenta measured with a tracking detector. The other analysis measures the angular distribution of electron pairs as a function of dielectron mass, gaining sensitivity over a probe of the mass spectrum alone. After reviewing several models that predict new neutral resonances, we discuss these CDF analyses and potential future applications.

Some theories of particle physics are so compelling that it is worth doing a comprehensive and systematic set of experimental searches to see if they are realized in nature. Supersymmetry is one such theory. This review focuses on the motivation for a broad set of cosmology-inspired search strategies at the Tevatron and on their implementation and results at the Collider Detector at Fermilab (CDF) with the first few fb^-1 of integrated luminosity of data.

The top quark is the heaviest known elementary particle. Observed for the first time in 1995 at the Tevatron by the CDF and D0 experiments, it has become object of several studies aimed to fully characterize its properties and decays. Precise determinations of top quark characteristics verify the internal consistency of the Standard Model (SM) and are sensitive to new physics phenomena. With the advent of the large top quark production rates generated at the LHC, top quark studies have reached unprecedented statistical precision. This review summarizes the recent measurements of top quark properties and studies of its decays performed at the LHC and Tevatron.

This review presents the world's most precise measurement of the W-boson mass m_W using data corresponding to ≈ 2.2 fb^-1 integrated luminosity collected with the CDF II detector at Fermi National Accelerator Laboratory (Fermilab). With samples of 470,126 W → eν candidates and 624,708 W → μν candidates, m_W is measured to be 80387±12_stat ± 15_syst = 80387 ± 19 MeV [Phys. Rev. Lett.108, 151803 (2012)]. This result significantly exceeds the precision of all previous measurements and improves the world averaged precision by 30%.

In this paper, we study the sensitivity of the fraction of events arising from gluon–gluon fusion to the chromoelectric and chromomagnetic dipole moments (CEDM and CMDM) as well as the total and differential cross-sections at the LHC and Tevatron. The sensitivity of measured charged asymmetry at the LHC to CEDM and CMDM is also studied. We find that at the Tevatron and the LHC, nonzero values of CMDM could suppress the production rate. It is shown that the ratio of at the Tevatron is more sensitive to CEDM and CMDM than the LHC case. The presence of CEDM always increases the contribution of gluon–gluon fusion process in top pair rate at the Tevatron and LHC. Except for a small range of CMDM, the presence of CEDM and CMDM can increase the fraction of gluon–gluon fusion at the Tevatron and LHC. The measured ratio of at the Tevatron is used to derive bounds on the chromoelectric and chromomagnetic dipole moments as well as the total and differential cross-sections at the LHC and Tevatron, and the measured charged asymmetry at the LHC. The combination of and σ_LHC provides stringent limits on CMDM and CEDM.

Recent measurements in the top quark sector at the Fermilab Tevatron collider are discussed. Measurements at the Tevatron use up to 9.7 fb^-1 of data corresponding to the full data sets recorded by each of the experiments, CDF and DØ. This review discusses the most recent measurements of inclusive and differential top quark cross-sections in strong and electroweak production of top quarks and related measurements, as well as measurements of angular distributions related to asymmetries in top quark production. Furthermore, the current status of precision measurements of the mass of the top quark is discussed. Where available, combinations of CDF and DØ results are presented.

The investigation of the dynamics responsible for electroweak symmetry breaking is one of the prime tasks of experiments at present and future colliders. Experiments at the Tevatron Collider and at the CERN Large Hadron Collider (LHC) must be able to discover a Standard Model Higgs boson over the full mass range as well as Higgs bosons in extended models. In this review, the discovery potential for the Standard Model Higgs boson and for Higgs bosons in the Minimal Supersymmetric extension is summarized. Emphasis is put on those studies which have been performed recently within the experimental collaborations using a realistic simulation of the detector performance. This includes a discussion of the search for Higgs bosons using the vector boson fusion mode at the LHC, a discussion of the measurement of Higgs boson parameters as well as a detailed review of the MSSM sector for different benchmark scenarios. The Tevatron part of the review also contains a discussion of first physics results from data taken in the ongoing Run II.

In this talk I review recent experimental and theoretical results in QCD. Since the topic is too vast to cover within given time constraints I choose to highlight some of the subjects that I find particularly exciting. On the experimental side I focus on measurements made at the Tevatron. Specifically jet production rates, and the cross section for B meson production. In addition I discuss an interesting measurement made by the Belle collaboration of double exclusive charmonium production. On the theory side I quickly review recent advances in computing hadronic cross sections at subleading order in perturbation theory. I then move on to soft-collinear effective theory. After a lightning review of the formalism I discuss recently published results on color-suppressed B → D decays.

We present measurements of the production cross section in b-tagged lepton + jets events from collisions at 1.96 TeV using the CDF detector at Fermilab. B-jets are tagged with either a secondary vertex algorithm, or a soft lepton tagger that identifies muons from B hadron semileptonic decays. With Tevatron Run II data, we estimate the signal fraction in two different ways: by estimating the various background contributions, and by fitting directly the leading jet transverse energy spectrum for the signal and background contributions. A subset of the sample, with two secondary vertex tagged jets, yields a production cross section consistent with the inclusive measurements. Results are consistent with a Standard Model signal and current measurements of the top quark mass.

Measurements of the production cross-section at in proton-antiproton collisions were performed by the CDF and DØ collaborations using final states where both W's decay hadronically. Each experiment uses luminosity of about 160 pb^-1 of data collected during Run II of the Fermilab Tevatron collider. Beside kinematical observables both experiments take advantage of identifying b jets based on lifetime tagging. While CDF counts the number of b-tags over background after a cut based analysis, DØ counts the excess of events after a neural network based kinematical selection and requiring a b-tagged jet.

CDF obtains ; .

A measurement of the ratio of branching fractions, R = B(t→Wb)/B(t→Wq), with q being any quark with I₃ = -1/2 and Q = -1/3, is presented. This analysis considers samples of single- and double-tagged lepton+jets events obtained with the DØ detector, corresponding to integrated luminosities of 169 pb^-1 and 158 pb^-1, respectively in the e+jets and μ+jets channels. Two different lifetime taggers, CSIP and SVT, are used.

We measure the mass of the top quark using 162 pb^-1 of data collected by the CDF experiment at the Fermilab Tevatron in Run II. The decay chain is studied using a novel technique called the Multivariate Template Method (MTM). Using this technique we obtain a result of for the top quark.

Using almost twice the luminosity of Run I, we present preliminary results on di-boson final states production at the Tevatron. These results include cross section measurements of most di-boson final states including the first measurement of WW cross section.

Results of a search for the Flavor-Changing Neutral Current decay using collision data at collected at Fermilab Tevatron collider by the CDF and DØ detectors are presented. CDF reports upper limits on and at the 95% C.L. using 171 pb^-1. The DØ Collaboration used 240 pb^-1 to set an even more stringent limit on the branching ratio for of 5.0 · 10^-7 at the 95% C.L.

Using 250 pb^-1 of data collected with the DØ detector in Run II of the Tevatron, the two narrow (L = 1) states, D₁(2420) and have been observed in semileptonic decays of B mesons. Results on the D*⁺ π^- decay mode are presented including a measurement of the branching fraction of B mesons to these states.

The DØ trigger system has been upgraded for Run II at the Tevatron. I present the current status of the DØ trigger.

Recent results for direct searches for physics beyond the Standard Model are reviewed. The results include Tevatron II data up to 1.2 fb^-1 and HERA results up to 350 pb^-1. Searches for Supersymmetry, for compositeness and for large extra dimensions are presented. The excess of events with an isolated lepton and high missing transverse momentum at HERA is discussed.