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Simultaneous Measurement Of The Ratio R = B(T → Wq) And The Top-Quark Pair Production Cross Section With The D0 Detector At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Simultaneous Measurement Of The Ratio R = B(T → Wq) And The Top-Quark Pair Production Cross Section With The D0 Detector At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Kenneth Bloom Publications
We present the first simultaneous measurement of the ratio of branching fractions, R = B(t → Wb)/B(t→Wq), with q being a d, s, or b quark, and the top-quark pair production cross section σtt in the lepton plus jets channel using 0.9 fb-1 of pp collision data at √s = 1.96 TeV collected with the D0 detector. We extract R and σtt by analyzing samples of events with 0, 1, and ≥ 2 identified b jets. We measure R=0.97-0.08+0.09(stat + syst) …
Measurement Of The Tt Production Cross Section In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Measurement Of The Tt Production Cross Section In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
We measure the tt production cross section in pp collisions at √s = 1.96 TeV in the lepton + jets channel. Two complementary methods discriminate between signal and background: b tagging and a kinematic likelihood discriminant. Based on 0.9 fb-1 of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure σtt = 7.62 ± 0.85 pb, assuming the current world average mt = 172.6 GeV. We compare our cross section measurement with theory predictions to determine a value for the top-quark mass of 170 ± 7 GeV.
Search For Excited Electrons In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Search For Excited Electrons In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
We present the results of a search for the production of an excited state of the electron, e*, in protonantiproton collisions at √s = 1.96 TeV. The data were collected with the D0 experiment at the Fermilab Tevatron Collider and correspond to an integrated luminosity of approximately 1 fb-1.We search for e* in the process pp → e*e, with the e* subsequently decaying to an electron plus photon. No excess above the standard model background is observed. Interpreting our data in the context of a model that describes e* …
A Combined Search For The Standard Model Higgs Boson At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
A Combined Search For The Standard Model Higgs Boson At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
We present new results of the search for WH → ℓνbb production in pp collisions at a center-of-mass energy of √s = 1.96 TeV, based on a dataset with integrated luminosity of 0.44 fb−1. We combine these new results with previously published searches by the D0 collaboration, for WH and ZH production analyzed in the ETbb final state, for ZH (→ℓ+ℓ-bb) production, for WH (→WWW) production, and for H (→WW) direct production. No signal-like excess is observed either in the WH analysis or in the combination …
Measurement Of The Forward-Backward Charge Asymmetry In Top-Quark Pair Production, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Measurement Of The Forward-Backward Charge Asymmetry In Top-Quark Pair Production, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
We present the first measurement of the integrated forward-backward charge asymmetry in top-quark– top-antiquark pair (tt) production in proton-antiproton (pp) collisions in the lepton + jets final state. Using a b-jet tagging algorithm and kinematic reconstruction assuming tt+ X production and decay, a sample of 0.9 fb-1 of data, collected by the D0 experiment at the Fermilab Tevatron Collider, is used to measure the asymmetry for different jet multiplicities. The result is also used to set upper limits on tt + X production via a Z’ resonance.
Search For Zz And ZΓ* Production In Pp Collisions At √S = 1.96 Tev And Limits On Anomalous Zzz And ZzΓ* Couplings, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Search For Zz And ZΓ* Production In Pp Collisions At √S = 1.96 Tev And Limits On Anomalous Zzz And ZzΓ* Couplings, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Kenneth Bloom Publications
We present a study of μμμμ, eeee, and μμee events using 1 fb-1 of data collected with the D0 detector at the Fermilab Tevatron pp Collider at √s = 1.96 TeV. Requiring the lepton pair masses to be greater than 30 GeV, we observe one event, consistent with the expected background of 0.13 ± 0.03 events and with the predicted standard model ZZ and Zγ* production of 1.71 ± 0.15 events. We set an upper limit on the ZZ and Zγ* cross section of 4.4 pb at the 95% C.L. We also derive limits …
Measurement Of The Shape Of The Boson-Transverse Momentum Distribution In Pp → Z/ Γ* = → E+E- + X Events Produced At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Measurement Of The Shape Of The Boson-Transverse Momentum Distribution In Pp → Z/ Γ* = → E+E- + X Events Produced At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
We present a measurement of the shape of the Z/γ* boson transverse momentum (qT) distribution in pp → Z/γ* → e+e- + X events at a center-of-mass energy of 1.96 TeVusing 0.98 fb-1 of data collected with the D0 detector at the Fermilab Tevatron collider. The data are found to be consistent with the resummation prediction at low qT, but above the perturbative QCD calculation in the region of qT > 30 GeV/c. Using events with qT < 30 GeV/c, we extract the value of g2, one …
Search For Flavor-Changing-Neutral-Current D Meson Decays, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Search For Flavor-Changing-Neutral-Current D Meson Decays, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Kenneth Bloom Publications
We study the flavor-changing-neutral-current process c → uμ+μ- using 1.3 fb-1 of pp collisions at √s = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the charged-current mediated D+s and D+ → φπ+ → μ+μ-π+ final states with significance greater than 4 standard deviations above background for the D+ state. We search for the continuum neutral-current decay of D+ → μ+μ-π+ in the dimuon invariant mass spectrum away …
Search For Randall-Sundrum Gravitons With1 Fb-1 Of Data From Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Search For Randall-Sundrum Gravitons With1 Fb-1 Of Data From Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Kenneth Bloom Publications
We search for decays of Kaluza-Klein excitations of the graviton in the Randall-Sundrum model of extra dimensions to e+e- and γγ in 1 fb-1 of pp collisions at √s = 1.96 TeV collected by the D0 detector at the Fermilab Tevatron. We set 95% confidence level upper limits on the production cross section times branching fraction, which translate into lower limits on the mass of the lightest excitation between 300 and 900 GeV for values of the coupling k/MP1 between 0.01 and 0.1.
Observation And Properties Of The Orbitally Excited B*S2 Meson, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Observation And Properties Of The Orbitally Excited B*S2 Meson, V. M. Abazov, Gregory R. Snow, Kenneth A. Bloom, D0 Collaboration
Kenneth Bloom Publications
We report the direct observation of the excited L = 1 state B*s2 in fully reconstructed decays to B+K-. The mass of the B*s2 meson is measured to be 5839.6 ± 1.1(stat) ± 0.7(syst) MeV/c2, and its production rate relative to the B+ meson is measured to be [1.15 ± 0.23(stat) ± 0.13(syst)]%.
Model-Independent Measurement Of The W-Boson Helicity In Top-Quark Decays At D0, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Model-Independent Measurement Of The W-Boson Helicity In Top-Quark Decays At D0, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
We present the first model-independent measurement of the helicity of W bosons produced in top quark decays, based on a 1 fb-1 sample of candidate tt events in the dilepton and lepton plus jets channels collected by the D0 detector at the Fermilab Tevatron pp Collider. We reconstruct the angle Ө* between the momenta of the down-type fermion and the top quark in the W boson rest frame for each top quark decay. A fit of the resulting cosӨ* distribution finds that the fraction of longitudinal W bosons ƒ0 = 0.425 ± 0.166(stat) ± 0.102(syst) …
Search For Squarks And Gluinos In Events With Jets And Missing Transverse Energy Using 2.1 Fb-1 Of Pp Collision Data At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Search For Squarks And Gluinos In Events With Jets And Missing Transverse Energy Using 2.1 Fb-1 Of Pp Collision Data At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
A data sample corresponding to an integrated luminosity of 2.1 fb-1 collected by the DØ detector at the Fermilab Tevatron Collider was analyzed to search for squarks and gluinos produced in pp collisions at a center-of-mass energy of 1.96 TeV. No evidence for the production of such particles was observed in topologies involving jets and missing transverse energy, and 95% C.L. lower limits of 379 GeV and 308 GeV were set on the squark and gluino masses, respectively, within the framework of minimal supergravity with tan β = 3, A0 = 0, and μ<0. The corresponding previous limits are improved by 54 GeV and 67 GeV.
Search For W’ Bosons Decaying To An Electron And A Neutrino With The D0 Detector, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Search For W’ Bosons Decaying To An Electron And A Neutrino With The D0 Detector, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Kenneth Bloom Publications
This Letter describes the search for a new heavy charged gauge boson W′ decaying into an electron and a neutrino. The data were collected with the D0 detector at the Fermilab Tevatron pp̅ Collider at √s = 1.96 TeV, and correspond to an integrated luminosity of about 1 fb-1. Lacking any significant excess in the data in comparison with known processes, an upper limit is set on σW′ x B(W′ → eν) and a W′ boson with mass below 1.00 TeV can be excluded at the 95% C.L., assuming standard-model-like couplings to fermions. This …
Measurement Of The Muon Charge Asymmetry From W Boson Decays, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Measurement Of The Muon Charge Asymmetry From W Boson Decays, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Kenneth Bloom Publications
We present a measurement of the muon charge asymmetry from W boson decays using 0.3 fb-1 of data collected at √s = 1.96 GeV between 2002 and 2004 with the D0 detector at the Fermilab Tevatron pp̅ Collider. We compare our findings with expectations from next-to-leading-order calculations performed using the CTEQ6.1M and MRST04 NLO parton distribution functions. Our findings can be used to constrain future parton distribution function fits.
Search For Supersymmetry In Di-Photon Final States At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Search For Supersymmetry In Di-Photon Final States At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
We report results of a search for supersymmetry (SUSY) with gauge-mediated symmetry breaking in di-photon events collected by the D0 experiment at the Fermilab Tevatron Collider in 2002–2006. In 1.1 fb-1 of data, we find no significant excess beyond the background expected from the standard model and set the most stringent lower limits to date for a standard benchmark model on the lightest neutralino and chargino masses of 125 GeV and 229 GeV, respectively, at 95% confidence.
Measurement Of The Ratios Of The Z/Γ*+≥N Jet Production Cross Sections To The Total Inclusive Z/Γ* Cross Section In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Measurement Of The Ratios Of The Z/Γ*+≥N Jet Production Cross Sections To The Total Inclusive Z/Γ* Cross Section In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
We present a study of events with Z bosons and associated jets produced at the Fermilab Tevatron collider in pp collisions at a center of mass energy of 1.96 TeV. The data sample consists of nearly 14 000 Z/γ*→e+e− candidates corresponding to an integrated luminosity of 0.4 fb-1 collected with the DØ detector. Ratios of the Z/γ*+≥n jet cross sections to the total inclusive Z/γ* cross section have been measured for n = 1–4 jets, and found to be in good agreement with a next-to-leading order QCD calculation and with a tree-level …
Search For The Lightest Scalar Top Quark In Events With Two Leptons In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Search For The Lightest Scalar Top Quark In Events With Two Leptons In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Kenneth Bloom Publications
Data collected by the D0 detector at a pp center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider have been used to search for pair production of the lightest supersymmetric partner of the top quark decaying into bℓν. The search is performed in the ℓℓ′ = eμ and μμ final states. No evidence for this process has been found in data samples of approximately 400 pb-1. The domain in the [M(t1),M(ν)] plane excluded at the 95% C.L. is substantially extended by this search.
The Cms Experiment At The Cern Lhc, S. Chatrchyan, Kenneth A. Bloom, Brian Bockelman, Daniel R. Claes, Aaron Dominguez, Michael Eads, Makoto Furukawa, J. Keller, T. Kelly, Carl Lundstedt, Sudhir Malik, Gregory Snow, David R. Swanson, Cms Collaboration
The Cms Experiment At The Cern Lhc, S. Chatrchyan, Kenneth A. Bloom, Brian Bockelman, Daniel R. Claes, Aaron Dominguez, Michael Eads, Makoto Furukawa, J. Keller, T. Kelly, Carl Lundstedt, Sudhir Malik, Gregory Snow, David R. Swanson, Cms Collaboration
Kenneth Bloom Publications
The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and leadlead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 1034 cm-2s-1 (1027 cm-2s-1). At the core of the CMS detector sits a high-magnetic field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations …