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Full-Text Articles in Physics
Search For Ultrahigh Energy Neutrinos In Highly Inclined Events At The Pierre Auger Observatory, P. Abreu, Emily B. Petermann, Gregory Snow, Pierre Auger Collaboration
Search For Ultrahigh Energy Neutrinos In Highly Inclined Events At The Pierre Auger Observatory, P. Abreu, Emily B. Petermann, Gregory Snow, Pierre Auger Collaboration
Gregory Snow Publications
The Surface Detector of the Pierre Auger Observatory is sensitive to neutrinos of all flavors above 0.1 EeV. These interact through charged and neutral currents in the atmosphere giving rise to extensive air showers. When interacting deeply in the atmosphere at nearly horizontal incidence, neutrinos can be distinguished from regular hadronic cosmic rays by the broad time structure of their shower signals in the water-Cherenkov detectors. In this paper we present for the first time an analysis based on down-going neutrinos. We describe the search procedure, the possible sources of background, the method to compute the exposure and the associated …
Measurement Of The Depth Of Maximum Of Extensive Air Showers Above 1018 Ev, J. Abraham, Gregory Snow, Pierre Auger Collaboration
Measurement Of The Depth Of Maximum Of Extensive Air Showers Above 1018 Ev, J. Abraham, Gregory Snow, Pierre Auger Collaboration
Gregory Snow Publications
We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 1018 eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106+35-21) g/cm2/decade below 1018.24 ±0.05 eV, and (24 ± 3) g/cm2/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 …
Transverse-Momentum And Pseudorapidity Distributions Of Charged Hadrons In Pp Collisions At √S=7 Tev, V. Khachatryan, Kenneth A. Bloom, S. Bose, J. Butt, Daniel R. Claes, Aaron Dominguez, Michael Eads, J. Keller, T. Kelly, Ilya Kravchenko, J. Lazo-Flores, Carl Lundstedt, H. Malbouisson, Sudhir Malik, Gregory Snow, Cms Collaboration
Transverse-Momentum And Pseudorapidity Distributions Of Charged Hadrons In Pp Collisions At √S=7 Tev, V. Khachatryan, Kenneth A. Bloom, S. Bose, J. Butt, Daniel R. Claes, Aaron Dominguez, Michael Eads, J. Keller, T. Kelly, Ilya Kravchenko, J. Lazo-Flores, Carl Lundstedt, H. Malbouisson, Sudhir Malik, Gregory Snow, Cms Collaboration
Gregory Snow Publications
Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at √s=7 TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dNch=dη ⃒|η|<0.5= 5.78 ± 0.01(stat) ± 0.23(syst) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from √s=0.9 to 7 TeV is [±66.1 ± 1.0(stat) ± 4.2(syst)]%. The mean transverse …
First Measurement Of Bose-Einstein Correlations In Proton-Proton Collisions At √S=0.9 And 2.36 Tev At The Lhc, V. Khachatryan, Kenneth A. Bloom, S. Bose, J. Butt, Daniel R. Claes, Aaron Dominguez, M. Eads, J. Keller, T. Kelly, Ilya Kravchenko, J. Lazo-Flores, C. Lundstedt, H. Malbouisson, S. Malik, Gregory Snow, Cms Collaboration
First Measurement Of Bose-Einstein Correlations In Proton-Proton Collisions At √S=0.9 And 2.36 Tev At The Lhc, V. Khachatryan, Kenneth A. Bloom, S. Bose, J. Butt, Daniel R. Claes, Aaron Dominguez, M. Eads, J. Keller, T. Kelly, Ilya Kravchenko, J. Lazo-Flores, C. Lundstedt, H. Malbouisson, S. Malik, Gregory Snow, Cms Collaboration
Gregory Snow Publications
Bose-Einstein correlations have been measured using samples of proton-proton collisions at 0.9 and 2.36 TeV center-of-mass energies, recorded by the CMS experiment at the CERN Large Hadron Collider. The signal is observed in the form of an enhancement of pairs of same-sign charged particles with small relative four-momentum. The size of the correlated particle emission region is seen to increase significantly with the particle multiplicity of the event.
Observation Of The Suppression Of The Flux Of Cosmic Rays Above 4 X 1019 Ev, J. Abraham, Gregory Snow, The Pierre Auger Collaboration
Observation Of The Suppression Of The Flux Of Cosmic Rays Above 4 X 1019 Ev, J. Abraham, Gregory Snow, The Pierre Auger Collaboration
Gregory Snow Publications
The energy spectrum of cosmic rays above 2.5 x 1018 eV, derived from 20 000 events recorded at the Pierre Auger Observatory, is described. The spectral index γ of the particle flux, J/ E- γ , at energies between 4 x 1018 eV and 4 x 1019 eV is 2.69 ± 0.02(stat) ± 0.06(syst), steepening to 4.2 ± 0.4(stat) ± 0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz’min.
Upper Limit On The Diffuse Flux Of Ultrahigh Energy Tau Neutrinos From The Pierre Auger Observatory, J. Abraham, Gregory Snow, Pierre Auger Collaboration
Upper Limit On The Diffuse Flux Of Ultrahigh Energy Tau Neutrinos From The Pierre Auger Observatory, J. Abraham, Gregory Snow, Pierre Auger Collaboration
Gregory Snow Publications
The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth’s crust. Tau leptons from ντ charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of ντ at EeV energies. Assuming an Eν-2 differential energy spectrum the limit set at 90% C.L. is Eν-2dNντ/dEν<1.3 x 10-7 GeV cm …
Search For Production Of Single Top Quarks Via Tcg And Tug Flavor-Changing-Neutral-Current Couplings, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Search For Production Of Single Top Quarks Via Tcg And Tug Flavor-Changing-Neutral-Current Couplings, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb-1 of lepton + jets data from pp̅ collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters Kgc/ Λ and Kgu/ Λ, where Kg define the strength of tcg …
Search For Production Of Single Top Quarks Via Tcg And Tug Flavor-Changing-Neutral-Current Couplings, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Search For Production Of Single Top Quarks Via Tcg And Tug Flavor-Changing-Neutral-Current Couplings, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb-1 of lepton + jets data from pp̅ collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters Kgc/ Λ and Kgu/ Λ, where Kg define the strength of tcg …
Search For Production Of Single Top Quarks Via Tcg And Tug Flavor-Changing-Neutral-Current Couplings, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Search For Production Of Single Top Quarks Via Tcg And Tug Flavor-Changing-Neutral-Current Couplings, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230 pb-1 of lepton + jets data from pp̅ collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters Kgc/ Λ and Kgu/ Λ, where Kg define the strength of tcg and tug couplings, and Λ defines the scale of new physics. …
Correlation Of The Highest-Energy Cosmic Rays With Nearby Extragalactic Objects, J. Abraham, Gregory Snow, Pierre Auger Collaboration
Correlation Of The Highest-Energy Cosmic Rays With Nearby Extragalactic Objects, J. Abraham, Gregory Snow, Pierre Auger Collaboration
Gregory Snow Publications
Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above 6 × 1019 electron volts and the positions of active galactic nuclei (AGN) lying within ~75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these cosmic rays with at least a 99% confidence level from a prescribed a priori test. The correlation we observed is compatible with the hypothesis that the highest-energy particles originate from nearby extragalactic sources whose flux has not been substantially reduced by interaction with the cosmic …
Search For A Higgs Boson Produced In Association With A Z Boson In Pp̅ Collisions, V. M. Abazov, Kenneth A. Bloom, Gregory Snow
Search For A Higgs Boson Produced In Association With A Z Boson In Pp̅ Collisions, V. M. Abazov, Kenneth A. Bloom, Gregory Snow
Gregory Snow Publications
We describe a search for the Standard Model Higgs boson with a mass of 105 GeV/c2 to 145 GeV/c2 in data corresponding to an integrated luminosity of approximately 450 pb-1 collected with the DØ detector at the Fermilab Tevatron p̅p collider at a center-of-mass energy of 1.96 TeV. The Higgs boson is required to be produced in association with a Z boson, and the Z boson is required to decay to either electrons or muons with the Higgs boson decaying to a b̅b pair. The data are well described by the expected background, leading to …
Measurement Of The ΛB0 Lifetime Using Semileptonic Decays, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Measurement Of The ΛB0 Lifetime Using Semileptonic Decays, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We report a measurement of the Λb0 lifetime using a sample corresponding to 1.3 fb-1 of data collected by the D0 experiment in 2002–2006 during run II of the Fermilab Tevatron collider. The Λb0 baryon is reconstructed via the decay Λb0 → μν̅Λc+ X. Using 4437 ± 329 signal candidates, we measure the Λb0 lifetime to be τ(Λb0) = 1.290-0.110+0.119 (stat) -0.091+0.087 (syst) ps, which is among the most precise measurements in semileptonic Λb0 decays. This result is in good …
Search For BS0→ Μ+ Μ- Decays At D0, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Search For BS0→ Μ+ Μ- Decays At D0, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We report results from a search for the decay Bs0 → μ+μ- using 1.3 fb-1 of pp̅ collisions at √s= 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron Collider.We find two candidate events, consistent with the expected background of 1.24 ± 0.99, and set an upper limit on the branching fraction of Ɓ(Bs0 → μ+μ-) < 1.2 x 10-7 at the 95% C.L.
Properties Of L = 1 B1 And B2* Mesons, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Properties Of L = 1 B1 And B2* Mesons, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
This Letter presents the first strong evidence for the resolution of the excited B mesons B1 and B2* as two separate states in fully reconstructed decays to B+(*). The mass of B1 is measured to be 5720.6 ± 2.4 ± 1.4 MeV=c 2 and the mass difference ΔM between B2* and B1 is 26.2 ± 3.1 ± 0.9 MeV/c 2, giving the mass of the B2* as 5746.8 ± 2.4 ± 1.7 MeV/c 2. The production rate for B1 and B2 …
Measurement Of The Top Quark Mass In The Dilepton Channel, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Measurement Of The Top Quark Mass In The Dilepton Channel, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration
Gregory Snow Publications
We present a measurement of the top quark mass in the dilepton channel based on approximately 370 pb-1 of data collected by the DØ experiment during Run II of the Fermilab Tevatron collider. We employ two different methods to extract the top quark mass. We show that both methods yield consistent results using ensemble tests of events generated with the DØ Monte Carlo simulation. We combine the results from the two methods to obtain a top quark mass mt = 178.1 ± 8.2 GeV. The statistical uncertainty is 6.7 GeV and the systematic uncertainty is 4.8 GeV.
Measurement Of The Pp̅→ Tt̅ + X Production Cross Section At √S = 1.96 Tev In The Fully Hadronic Decay Channel, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Measurement Of The Pp̅→ Tt̅ + X Production Cross Section At √S = 1.96 Tev In The Fully Hadronic Decay Channel, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
A measurement of the top quark pair production cross section in proton antiproton collisions at an interaction energy of √s= 1.96 TeV is presented. This analysis uses 405 ± 25 pb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. Fully hadronic tt̅ decays with final states of six or more jets are separated from the multijet background using secondary vertex tagging and a neural network. The tt̅ cross section is measured as σ tt̅= 4.5-1.9+2.0(stat)-1.1+1.4(syst) ± 0.3(lumi) pb for a top quark mass of mt …
Measurement Of The ΛB Lifetime In The Exclusive Decay ΛB→ J/Ψλ, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Measurement Of The ΛB Lifetime In The Exclusive Decay ΛB→ J/Ψλ, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
Λ are identified via the decays J/ψ → μ+μ- and Λ →pπ, we measured the Λb lifetime to be 1.218-0.115+0.130 (stat) ± 0.042(syst) ps. We also measured the B0 lifetime in the decay B0 → J/ψ(μ+μ-)Ks2(π+π-) to be τ(B0) = 1.501-0.074+0.078 (stat) ± 0.050(syst) ps, yielding a lifetime ratio of τ(Λb)/τ(B0) = 0.811-0.087+0.096 (stat) ± 0.034(syst).
Search For Stopped Gluinos From Pp̅ Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Search For Stopped Gluinos From Pp̅ Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles’ decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g̃), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb-1 of pp̅ collisions at √s = 1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron …
Combined D0 Measurements Constraining The Cp-Violating Phase And Width Difference In The BS0 System, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Combined D0 Measurements Constraining The Cp-Violating Phase And Width Difference In The BS0 System, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We combine the D0 measurement of the width difference between the light and heavy Bs0 mass eigenstates and of the CP-violating mixing phase determined from the time-dependent angular distributions in the Bs0 → J/ψφ decays along with the charge asymmetry in semileptonic decays also measured with the D0 detector. With the additional constraint from the world average of the flavor-specific Bs0 lifetime, we obtain ΔΓs ≡ (ΓL - ΓH) = 0.13 ± 0.09 ps-1 and ∣φs∣ = 2.44-0.39+0.47. The data sample corresponds …
Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions Using Dilepton Events, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions Using Dilepton Events, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We present a measurement of the tt̅ pair production cross section in pp̅ collisions at √s = 1.96 TeV utilizing approximately 425 pb-1 of data collected with the D0 detector. We consider decay channels containing two high pT charged leptons (either ℯ or μ) from leptonic decays of both top-daughter W bosons. These were gathered using four sets of selection criteria, three of which required that a pair of fully identified leptons (i.e., ℯμ, ℯℯ, or μμ) be found. The fourth approach imposed less restrictive criteria on one of the lepton candidates and required that at least …
The Cosmic Ray Observatory Project: A Statewide Outreach And Education Ex-Periment In Nebraska, Daniel Claes, Gregory Snow
The Cosmic Ray Observatory Project: A Statewide Outreach And Education Ex-Periment In Nebraska, Daniel Claes, Gregory Snow
Gregory Snow Publications
Abstract: The Cosmic Ray Observatory Project (CROP) is a statewide education and research ex-periment involving Nebraska high school students, teachers and university undergraduates in the study of extensive cosmic-ray air showers. A network of high school teams construct, install, and op-erate school-based detectors in coordination with University of Nebraska physics professors and graduate students. The detector system at each school is an array of scintillation counters recycled from the Chicago Air Shower Array in weather-proof enclosures on the school roof, with a GPS re-ceiver providing a time stamp for cosmic-ray events. The detectors are connected to triggering elec-tronics and a …
The Cosmic Ray Observatory Project: A Statewide Outreach And Education Experiment In Nebraska, Daniel R. Claes, Gregory R. Snow
The Cosmic Ray Observatory Project: A Statewide Outreach And Education Experiment In Nebraska, Daniel R. Claes, Gregory R. Snow
Gregory Snow Publications
The Cosmic Ray Observatory Project (CROP) is a statewide education and research experiment involving Nebraska high school students, teachers and university undergraduates in the study of extensive cosmic-ray air showers. A network of high school teams construct, install, and operate school-based detectors in coordination with University of Nebraska physics professors and graduate students. The detector system at each school is an array of scintillation counters recycled from the Chicago Air Shower Array in weather-proof enclosures on the school roof, with a GPS receiver providing a time stamp for cosmic-ray events. The detectors are connected to triggering electronics and a data-acquisition …
Correlation Of The Highest-Energy Cosmic Rays With Nearby Extragalactic Objects, J. Aberham, Gregory Snow, The Pierre Auger Collaboration
Correlation Of The Highest-Energy Cosmic Rays With Nearby Extragalactic Objects, J. Aberham, Gregory Snow, The Pierre Auger Collaboration
Gregory Snow Publications
Cosmic rays are particles and nuclei that bombard the Earth from space in all directions (1). A few have astounding energies—beyond 100 EeV (1 EeV = 1 exa-electron volt = 1018 eV)—orders of magnitude beyond even the future capabilities of any earthly particle accelerator. Such energies are so extreme that they could arise in only the most violent places in the universe. One possible location is within active galactic nuclei (AGN), galaxies hosting central black holes that feed on gas and stars and may eject vast plasma jets into intergalactic space.
Combination Of Cdf And D0 Results On The W Boson Mass And Width, V. M. Abazov, Gregory Snow, D0 Collaboration
Combination Of Cdf And D0 Results On The W Boson Mass And Width, V. M. Abazov, Gregory Snow, D0 Collaboration
Gregory Snow Publications
The results based on 1992–95 data (Run 1) from the CDF and D0 experiments on the measurements of the W boson mass and width are presented, along with the combined results. We report a Tevatron collider average Mw = 80.456 ± 0.059 GeV. We also report the Tevatron collider average of the directly measured W boson width Γw = 2.115 ± 0.105 GeV. We describe a new joint analysis of the direct W mass and width measurements. Assuming the validity of the standard model, we combine the directly measured W boson width with the width extracted from the …
Measurement Of The Ratio Of Inclusive Cross Sections Σ(Pp̅ → Z + B Jet)/Σ(Pp̅ → Z + Jet) At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Measurement Of The Ratio Of Inclusive Cross Sections Σ(Pp̅ → Z + B Jet)/Σ(Pp̅ → Z + Jet) At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
Using the data collected with the D0 detector at √s = 1.96 TeV, for integrated luminosities of about 180 pb-1, we have measured the ratio of inclusive cross sections for pp̅ → Z + b jet to pp̅ → Z + jet production. The inclusive Z + b-jet reaction is an important background to searches for the Higgs boson in associated ZH production at the Fermilab Tevatron collider. Our measurement is the first of its kind, and relies on the Z → ℯ+ℯ- and Z → μ+μ- modes. The combined …
Search For First-Generation Scalar Leptoquarks In (Pp̅ Collisions At√S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Search For First-Generation Scalar Leptoquarks In (Pp̅ Collisions At√S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We report on a search for pair production of first-generation scalar leptoquarks (LQ) in pp̅ collisions at √s = 1.96 TeV using an integrated luminosity of 252 pb-1 collected at the Fermilab Tevatron collider by the D0 detector. We observe no evidence for LQ production in the topologies arising from LQL̅Q̅ → ℯqℯq and LQL̅Q̅ → ℯqνq, and derive 95% C.L. lower limits on the LQ mass as a function of β, where β is the branching fraction for LQ → ℯq. The limits are 241 and 218 GeV/c2 for β = 1 and …
Measurement Of The Ww Production Cross Section In Pp̅ Collisions At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Measurement Of The Ww Production Cross Section In Pp̅ Collisions At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We present a measurement of the W boson pair-production cross section in pp̅ collisions at a center-of- mass energy of √s = 1.96 TeV. The data, collected with the Run II D0 detector at Fermilab, correspond to an integrated luminosity of 224–252 pb-1 depending on the final state (ℯℯ, ℯμ, or μμ). We observe 25 candidates with a background expectation of 8.1 ± 0.6(stat) ± 0.6(syst) ± 0.5(lum) events. The probability for an upward fluctuation of the background to produce the observed signal is 2.3 x 10-7, equivalent to 5.2 standard deviations. The measurement yields a …
Search For Anomalous Heavy-Flavor Quark Production In Association With W Bosons, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Search For Anomalous Heavy-Flavor Quark Production In Association With W Bosons, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We search for anomalous production of heavy-flavor quark jets in association with W bosons at the Fermilab Tevatron pp̅ Collider in final states in which the heavy-flavor quark content is enhanced by requiring at least one tagged jet in an event. Jets are tagged using one algorithm based on semileptonic decays of b/c hadrons, and another on their lifetimes. We compare ℯ+ jets (164 pb-1) and μ+ jets (145 pb-1) channels collected with the D0 detector at √s = 1.96 TeV to expectations from the standard model and set upper limits …
Measurement Of Σ(Pp̅→Z)•Br(Z→ Ττ) At √S = 1.96tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Measurement Of Σ(Pp̅→Z)•Br(Z→ Ττ) At √S = 1.96tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration
Gregory Snow Publications
We present a measurement of the cross section for Z production times the branching fraction to _ leptons, σ•Br(Z → τ+τ-), in pp̅ collisions at √s = 1.96 TeV in the channel in which one τ decays into μνμντ, and the other into hadrons +ντ or ℯνℯντ. The data sample corresponds to an integrated luminosity of 226 pb-1 collected with the D0 detector at the Fermilab Tevatron collider. The final sample contains 2008 candidate events with an estimated background of 55%. From this we …
Measurement Of The ΛB0 Lifetime In The Decay ΛB0 → J/Ψλ0 With The D0 Detector, V. M. Abazov, Gregory Snow, D0 Collaboration
Measurement Of The ΛB0 Lifetime In The Decay ΛB0 → J/Ψλ0 With The D0 Detector, V. M. Abazov, Gregory Snow, D0 Collaboration
Gregory Snow Publications
We present measurements of the Λb0 lifetime in the exclusive decay channel Λb0 → J/ψΛ0, with J/ψ → μ+μ- and Λ0 → pπ-, the B0 lifetime in the decay Λ0 → J/ψKs0 with J/ψ → μ+μ- and Ks0 → π+π-, and the ratio of these lifetimes. The analysis is based on approximately 250 pb-1 of data recorded with the D0 detector in pp̅ collisions at √s = …