0000000001209608
AUTHOR
D. Jang
showing 19 related works from this author
Search for Charged Higgs Bosons in Decays of Top Quarks inpp¯Collisions ats=1.96 TeV
2009
We report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb{sup -1} collected by the CDF II detector at Fermilab, and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at {Beta}(t {yields} H{sup +}b) < 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c{sup 2}, assuming {Beta}(H{sup +} {yields} c{bar s}) = 1.0. The upper…
Search forWWandWZResonances Decaying to Electron, MissingET, and Two Jets inpp¯Collisions ats=1.96 TeV.
2009
We present a search for WW and WZ production in final states that contain a charged lepton (electron or muon) and at least two jets, produced in {radical}(s)=1.96 TeV pp collisions at the Fermilab Tevatron, using data corresponding to 1.2 fb{sup -1} of integrated luminosity collected with the CDF II detector. Diboson production in this decay channel has yet to be observed at hadron colliders due to the large single W plus jets background. An artificial neural network has been developed to increase signal sensitivity, as compared with an event selection based on conventional cuts. We set a 95% confidence level upper limit of {sigma}{sub WW}xBR(W{yields}l{nu}{sub l},W{yields}jets)+{sigma}{sub…
Study of the associated production of photons andb-quark jets inpp¯collisions ats=1.96 TeV
2010
The cross section for photon production in association with at least one jet containing a b quark has been measured in proton antiproton collisions at {radical}(s)=1.96 TeV. The data sample used corresponds to an integrated luminosity of 340 pb{sup -1} collected with the CDF II detector. Both the differential cross section as a function of photon transverse energy E{sub T}{sup {gamma}}and the total cross section are measured and compared to a next-to-leading order prediction for the process.
Precision Measurement of theX(3872)Mass inJ/ψπ+π−Decays
2009
We present an analysis of the mass of the X(3872) reconstructed via its decay to J/psi pi(+)pi(-) using 2.4 fb(-1) of integrated luminosity from p (p) over bar collisions at root s = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. The possible existence of two nearby mass states is investigated. Within the limits of our experimental resolution the data are consistent with a single state, and having no evidence for two states we set upper limits on the mass difference between two hypothetical states for different assumed ratios of contributions to the observed peak. For equal contributions, the 95% confidence level upper limit on the mass difference is 3.6 MeV/c(2). Un…
Search for the Higgs Boson Using Neural Networks in Events with Missing Energy andb-Quark Jets inpp¯Collisions ats=1.96 TeV
2010
We report on a search for the standard model Higgs boson produced in association with a W or Z boson in p{bar p} collisions at {radical}s = 1.96 TeV recorded by the CDF II experiment at the Tevatron in a data sample corresponding to an integrated luminosity of 2.1 fb{sup -1}. We consider events which have no identified charged leptons, an imbalance in transverse momentum, and two or three jets where at least one jet is consistent with originating from the decay of a b hadron. We find good agreement between data and predictions. We place 95% confidence level upper limits on the production cross section for several Higgs boson masses ranging from 110 GeV/c{sup 2} to 150 GeV/c{sup 2}. For a ma…
Combination of CDF and D0 measurements of the W boson helicity in top quark decays
2012
Aaltonen, T. et al.
Observation and Mass Measurement of the BaryonΞb−
2007
We report the observation and measurement of the mass of the bottom, strange baryon $\Xi^-_b$ through the decay chain $\Xi^-_b \to J/\psi \Xi^-$, where $J/\psi \to \mu^+ \mu^-$, $\Xi^- \to \Lambda \pi^-$, and $\Lambda \to p \pi^-$. Evidence for observation is based on a signal whose probability of arising from the estimated background is 6.6 x 10^{-15}, or 7.7 Gaussian standard deviations. The $\Xi^-_b$ mass is measured to be $5792.9\pm 2.5$ (stat.) $\pm 1.7$ (syst.) MeV/$c^2$.
Inclusive Search for Standard Model Higgs Boson Production in the WW Decay Channel using the CDF II Detector
2010
We present a search for standard model (SM) Higgs boson production using p (p) over bar collision data at root s = 1. 96 TeV, collected with the CDF II detector and corresponding to an integrated luminosity of 4. 8 fb(-1). We search for Higgs bosons produced in all processes with a significant production rate and decaying to two W bosons. We find no evidence for SM Higgs boson production and place upper limits at the 95% confidence level on the SM production cross section (sigma(H)) for values of the Higgs boson mass (m(H)) in the range from 110 to 200 GeV. These limits are the most stringent for m(H) > 130 GeV and are 1.29 above the predicted value of sigma(H) for m(H) 165 GeV.
Observation of theΩb−baryon and measurement of the properties of theΞb−andΩb−baryons
2009
The authors report the observation of the bottom, doubly-strange baryon {Omega}{sub b}{sup -} through the decay chain {Omega}{sub b}{sup -} {yields} J/{psi}{Omega}{sup -}, where J/{psi} {yields} {mu}{sup +} {mu}{sup -}, {Omega}{sup -} {yields} {Lambda}K{sup -}, and {Lambda} {yields} p {pi}{sup -}, using 4.2 fb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 x 10{sup -8}, or 5.5 Gaussian standard deviations. The {Omega}{sub b}{sup -} mass is measured to be 6054.4 {+-} 6.8(stat.) {+-} 0.9(syst.) MeV/c{sup 2}. The lifetime of the {Omega}…
First measurement of the W-boson mass in run II of the Tevatron.
2007
7 pages, 4 figures.-- PACS nrs.: 14.70.Fm; 13.38.Be; 13.85.Qk.-- ISI Article Identifier: 000250140600014.-- ArXiv pre-print available at: http://arxiv.org/abs/0707.0085.-- et al.
Tevatron Run II combination of the effective leptonic electroweak mixing angle
2018
The Ministry of Science and Innovation and the Consolider-Ingenio 2010 Program and the European Union community Marie Curie Fellowship Contract No. 302103.
Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron
2018
The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of √s=1.96 TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is At¯tFB=0.128±0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.
Measurement of the top quark mass using the invariant mass of lepton pairs in soft muon b-tagged events
2009
We present the first measurement of the mass of the top quark in a sample of t (t) over bar -> l (nu) over barb (b) over barq (q) over bar events (where l = e, mu) selected by identifying jets containing a muon candidate from the semileptonic decay of heavy-flavor hadrons (soft muon b tagging). The p (p) over bar collision data used correspond to an integrated luminosity of 2 fb(-1) and were collected by the CDF II detector at the Fermilab Tevatron Collider. The measurement is based on a novel technique exploiting the invariant mass of a subset of the decay particles, specifically the lepton from the W boson of the t -> Wb decay and the muon from a semileptonic b decay. We fit template hist…
Direct Top-Quark Width Measurement at CDF
2010
7 páginas, 2 figuras, 2 tablas.-- CDF Collaboration: et al.
Top quark mass measurement in the lepton plus jets channel using a modified matrix element method
2008
We report a measurement of the top quark mass, m(t), obtained from p(p)over bar collisions at root s=1.96 TeV at the Fermilab Tevatron using the CDF II detector. We analyze a sample corresponding to an integrated luminosity of 1.9 fb(-1). We select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. We calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. Our event likelihood is a function of m(t) and a parame…
Cross section measurements of high-p(T) dilepton final-state processes using a global fitting method
2008
We present a new method for studying high-$p_T$ dilepton events ($e^{\pm}e^{\mp}$, $\mu^{\pm}\mu^{\mp}$, $e^{\pm}\mu^{\mp}$) and simultaneously extracting the production cross sections of $p\bar{p} \to t\bar{t}$, $p\bar{p} \to W^+W^-$, and $p\bar{p} \to \ztt$ at a center-of-mass energy of $\sqrt{s} = 1.96$ TeV. We perform a likelihood fit to the dilepton data in a parameter space defined by the missing transverse energy and the number of jets in the event. Our results, which use $360 {\rm pb^{-1}}$ of data recorded with the CDF II detector at the Fermilab Tevatron Collider, are $\sigma(t\bar{t}) = 8.5_{-2.2}^{+2.7}$ pb, $\sigma(W^+W^-) = 16.3^{+5.2}_{-4.4}$ pb, and $\sigma(\ztt) =291^{+50}_…
Search for Anomalous Production of Events with a Photon, Jet, b-quark Jet, and Missing Transverse Energy
2009
We present a signature-based search for the anomalous production of events containing a photon, two jets, of which at least one is identified as originating from a b quark, and missing transverse energy ((sic)(T)). The search uses data corresponding to 2.0 fb(-1) of integrated luminosity from p (p) over bar collisions at a center-of-mass energy of root s = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. From 6.697 47 x 10(6) events with a photon candidate with transverse energy E-T > 25 GeV, we find 617 events with (sic)(T) > 25 GeV and two or more jets with E-T > 15 GeV, at least one identified as originating from a b quark, versus an expectation of 607 +/- 113 event…
Search for new particles decaying into dijets in proton-antiproton collisions at root s=1.96 TeV
2009
We present a search for new particles which produce narrow two-jet (dijet) resonances using proton-antiproton collision data corresponding to an integrated luminosity of 1.13 fb(-1) collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude vertical bar y vertical bar < 1. These limits are used to determine the mass exclusions for the excited quark, axig…
First Observation of Vector Boson Pairs in a Hadronic Final State at the Tevatron Collider
2009
We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V=W, Z) where one boson decays to a dijet final state. The data correspond to 3.5 fb(-1) of integrated luminosity of pp collisions at s=1.96 TeV collected by the CDF II detector at the Fermilab Tevatron. We observe 1516 +/- 239(stat)+/- 144(syst) diboson candidate events and measure a cross section sigma(pp -> VV+X) of 18.0 +/- 2.8(stat)+/- 2.4(syst)+/- 1.1(lumi) pb, in agreement with the expectations of the standard model.