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Series

Kenneth Bloom Publications

1999

Articles 1 - 15 of 15

Full-Text Articles in Physics

Measurement Of The B00 Oscillation Frequency Using L-D*+ Pairs And Lepton Flavor Tags, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Dec 1999

Measurement Of The B0B̅0 Oscillation Frequency Using L-D*+ Pairs And Lepton Flavor Tags, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

The oscillation frequency Δmd of B00 mixing is measured using the partially reconstructed semileptonic decay 0l- ν̅ D*+X. The data sample was collected with the CDF detector at the Fermilab Tevatron collider during 1992–1995 by triggering on the existence of two lepton candidates in an event, and corresponds to about 110 pb-1 of p̅p collisions at √s =1.8 TeV. We estimate the proper decay time of the 0 meson from the measured decay length and reconstructed momentum of the l-D*+ system. The charge of …


Measurement Of B Quark Fragmentation Fractions In The Production Of Strange And Light B Mesons In Pp̅ Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Nov 1999

Measurement Of B Quark Fragmentation Fractions In The Production Of Strange And Light B Mesons In Pp̅ Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

A new technique to measure the ratio of b quark fragmentation fractions in pp̅ collisions is described. Using a 70-pb-1 sample of low-mass dimuon trigger data recorded with the Collider Detector at Fermilab, we identify B mesons by observing the double semileptonic decays bcμX with csμ X. By counting the numbers of K*(892) 0, K*(892) 1, and Φ (1020) mesons produced in association with these muon pairs, we measure the ratio of strange to nonstrange B meson production to be fs /( fu+ i>fd)=[21.0±3.6(stat) -3.0 …


Search For The Flavor-Changing Neutral Current Decays B+→ Μ+Μ-K+ And B0→ Μ+Μ-K*0, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Oct 1999

Search For The Flavor-Changing Neutral Current Decays B+→ Μ+Μ-K+ And B0→ Μ+Μ-K*0, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report on a search for the flavor-changing neutral current decays B+→ μ+μ-K+ and i>B0→ μ+μ-K*0 using 88 pb-1 of data from p̅p collisions at √s =1.8 TeV, collected with the Collider Detector at Fermilab. Finding no evidence for these decays, we set upper limits on the branching fractions Ɓ(B+→ μ+μ-K+) < 5.2 X 10-6 and Ɓ(B+→ μ+μ-K*0) -6 at the 90% confidence level.


Search For A Technicolor ΩT Particle In Events With A Photon And A B-Quark Jet At Fermilab, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Oct 1999

Search For A Technicolor ΩT Particle In Events With A Photon And A B-Quark Jet At Fermilab, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

If the technicolor ωT particle exists, a likely decay mode is ωT→ γπT , followed by πTbb̅, yielding the signature γbb̅. We have searched 85 pb-1 of data collected by the CDF experiment at the Fermilab Tevatron for events with a photon and two jets, where one of the jets must contain a secondary vertex implying the presence of a b quark. We find no excess of events above standard model expectations. We express the result as an exclusion region in the MωT -MπT …


Measurement Of B0-B̅0 Flavor Oscillations Using Jet-Charge And Lepton Flavor Tagging In Pp̅ Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Oct 1999

Measurement Of B0-B̅0 Flavor Oscillations Using Jet-Charge And Lepton Flavor Tagging In Pp̅ Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of the mass difference Δmd for the B0 meson and the statistical power of the b flavor tagging methods used. The measurement uses 90 pb-1 of data from pp̅ collisions at √s =1.8 TeV collected with the CDF detector. An inclusive lepton trigger is used to collect a large sample of B hadron semileptonic decays. The mass difference Δmd is determined from the proper time dependence of the fraction of B hadrons that undergo flavor oscillations. The flavor at decay is inferred from the charge of the lepton from semileptonic …


Search For R-Parity Violating Supersymmetry Using Like-Sign Dielectrons In Pp̅ Collisions At √S = 1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Sep 1999

Search For R-Parity Violating Supersymmetry Using Like-Sign Dielectrons In Pp̅ Collisions At √S = 1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a search for like-sign dielectron plus multijet events using 107 pb-1 of data in pp̅ collisions at √s =1.8 TeV collected in 1992–1995 by the CDF experiment. Finding no events that pass our selection, we set σ X BR limits on two supersymmetric processes that can produce this experimental signature: gluino-gluino or squark-antisquark production with R-parity violating decays of the charm squark or lightest neutralino via a nonzero λ′121 coupling. We compare our results to the next-to-leading order calculations for gluino and squark production cross sections and set lower limits on M (g̃), M (t̃ …


Measurement Of The BD0D0 Oscillation Frequency Using Dimuon Data In Pp̅ Collisions At √S =1.8tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Sep 1999

Measurement Of The BD0B̅D0 Oscillation Frequency Using Dimuon Data In Pp̅ Collisions At √S =1.8tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of the mass difference Δmd of the two Bd0 mass eigenstates. We use a flavor tagging method based on the lepton charge, in a sample of events with two muons at low transverse momentum. The sample corresponds to an integrated luminosity of 90 pb-1 collected by the Collider Detector at Fermilab. The result obtained is Dmd=0.503±0.064(stat) ±0.071(syst) ps-1.


Online Track Processor For The Cdf Upgrade, C. Ciobanu, J. Gerstenslager, J. Hoftiezer, R. Hughes, M. Johnson, P. Koehn, C. Neu, C. Sanchez, B.L. Winer, J. Freeman, S. Holm, J.D. Lewis, T. Shaw, T. Wesson, Kenneth A. Bloom, D. Gerdes, J.W. Dawson, W.N. Haberichter Aug 1999

Online Track Processor For The Cdf Upgrade, C. Ciobanu, J. Gerstenslager, J. Hoftiezer, R. Hughes, M. Johnson, P. Koehn, C. Neu, C. Sanchez, B.L. Winer, J. Freeman, S. Holm, J.D. Lewis, T. Shaw, T. Wesson, Kenneth A. Bloom, D. Gerdes, J.W. Dawson, W.N. Haberichter

Kenneth Bloom Publications

A trigger track processor is being designed for the CDF upgrade. This processor identifies high momentum (PT > 1.5 GeV/c) charged tracks in the new central outer tracking chamber for CDF 11. The track processor is called the extremely Fast Tracker (XFT). The XFT design is highly parallel to handle the input rate of 183 Gbits/sec and output rate of 44 Gbitslsec. The processor is pipelined and reports the results for a new event every 132 ns. The processor uses three stages, hit classification, segment finding, and segment linking. The pattern recognition algorithms for the three stages are implemented …


Search For BS0-B̅S0, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration May 1999

Search For BS0-B̅S0, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

A search for Bs0-B̅s0 oscillations is performed in a sample of Bs0 semileptonic decays collected using dilepton triggers at the Tevatron Collider during 1992–1995. The Bs0 is reconstructed using φ mesonlepton correlations; its initial production flavor is determined with the second lepton in the event. From a signal of 1068 with a Bs0 purity of 61%, we obtain a limit on the Bs0-B̅s0 oscillation frequency of Δms>5.8 ps-1 at 95% confidence level.


Kinematics Of Tt̅ Events At Cd, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration May 1999

Kinematics Of Tt̅ Events At Cd, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

The kinematic properties of tt̅ events are studied in the W + multijet channel using data collected with the CDF detector during the 1992–1995 runs at the Fermilab Tevatron collider corresponding to an integrated luminosity of 109 pb-1. Distributions of a variety of kinematic variables chosen to be sensitive to different aspects of tt̅ production are compared with those expected from Monte Carlo calculations. A sample of 34 events rich in tt̅ pairs is obtained by requiring at least one jet identified by the silicon vertex detector (SVX) as having a displaced vertex consistent with the decay of …


Search For Third-Generation Leptoquarks From Technicolor Models In Pp̅ Collisions At √S = 1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Apr 1999

Search For Third-Generation Leptoquarks From Technicolor Models In Pp̅ Collisions At √S = 1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report the results of a search for technicolor using 110 pb-1 of pp̅ collisions recorded by the Collider Detector at Fermilab (CDF). In technicolor models containing a technifamily, color-octet technirhos enhance the pair production of color-triplet technipions, which behave as third-generation leptoquarks. From our previously reported search for third-generation leptoquarks, we present constraints on the production of color-triplet technipions and color-octet technirhos as a function of their masses.


Search For New Particles Decaying To Bb̅ In Pp̅ Collisions At √S = 1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Mar 1999

Search For New Particles Decaying To Bb̅ In Pp̅ Collisions At √S = 1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We have used 87 pb-1 of data collected with the collider detector at Fermilab to search for new particles decaying to bb̅. We present model-independent upper limits on the cross section for narrow resonances which exclude the color-octet technirho in the mass interval 350 < M < 440 GeV/c2. In addition, we exclude top-gluons, predicted in models of top-color-assisted technicolor, of width Γ= 0.3M in the mass range 280 < M < 670 GeV/c2, of width Γ= 0.5M in the mass range 340 < M < 640 GeV/c2, and of width Γ= 0.7M in the mass range 375 < M < 560 GeV/c2.


Measurement Of ZT0 And Drell-Yan Production Cross Sections Using Dimuons In P̅P Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Mar 1999

Measurement Of ZT0 And Drell-Yan Production Cross Sections Using Dimuons In P̅P Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of Z0 boson and Drell-Yan production cross sections in p̅p collisions at √s =1.8 TeV using a sample of 107 pb-1 accumulated by the Collider Detector at Fermilab. The Drell-Yan cross section is measured in the mass range of Mμμ>40 GeV/c2. We compare the measurements with the predictions of quantum chromodynamics in both leading order and next-to-leading order, incorporating the recent parton distribution functions. The measurements are consistent with the standard model expectations.


Measurement Of The Mass Splittings Between The Bb̅ΧB,J(1P) States, K. W. Edwards, Kenneth A. Bloom, Cleo Collaboration Feb 1999

Measurement Of The Mass Splittings Between The Bb̅ΧB,J(1P) States, K. W. Edwards, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We present new measurements of photon energies and branching fractions for the radiative transitions Υ(2S) → γχb(J=0,1,2)(1P). The masses of the χb states are determined from the measured radiative photon energies. The ratio of mass splittings between the χb substates, r ≡ [(MJ=2 -MJ=1)/( MJ=1 - MJ=0), with M the χb mass, provides information on the nature of the bb̅ confining potential. We find r(1P)=0.542 ±0.022±0.024. This value is somewhat lower than the previous world average, but more consistent with …


Measurement Of The Top Quark Mass With The Collider Detector At Fermilab, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Jan 1999

Measurement Of The Top Quark Mass With The Collider Detector At Fermilab, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a new measurement of the top quark mass in tt̅ events in which both W bosons from top quarks decay into leptons (eν, μν). We use events collected by the CDF experiment from pp̅ collisions at √s =1.8 TeV at the Tevatron collider. We measure a top quark mass of 167.4 ± 10.3(stat) ± 4.8(syst) GeV/c2 from a sample of eight events. We combine this result with previous CDF measurements in other decay channels to obtain a final mass value of 176.0 ± 6.5 GeV/c2.