135 Matching Results

Search Results

Advanced search parameters have been applied.
in creator/contributor: "Abbott, B."  
Results: 1 - 24 next
open access

Measurement of the t anti-t production cross section and top quark mass extraction using dilepton events in p anti-p collisions

Description: We present a measurement of the top quark pair production cross section in p{bar p} collisions at {radical}s = 1.96 TeV using approximately 1 fb{sup -1} of data collected with the D0 detector. We consider decay channels containing two high p{sub T} charged leptons where one lepton is identified as an electron or a muon while the other lepton can be an electron, a muon or a hadronically decaying {tau} lepton. For a mass of the top quark of 170 GeV, the measured cross section is 7.5{sub -1.0}{sup… more
Date: January 1, 2009
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Evidence for production of single top quarks

Description: We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron p{bar p} collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top quark partner that is always produced from strong coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top quark production has been searched for in ever lar… more
Date: March 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Measurement of the forward-backward charge asymmetry and extraction of $sin^2Theta^{eff}_W$ in $p\bar{p} \to Z/\gamma^{*}+X \to e^+e^-+X$ events produced at $\sqrt{s}=1.96$ TeV

Description: We present a measurement of the forward-backward charge asymmetry (A{sub FB}) in p{bar p} {yields} Z/{gamma}* + X {yields} e{sup +}e{sup -} + X events at a center-of-mass energy of 1.96 TeV using 1.1 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider. A{sub FB} is measured as a function of the invariant mass of the electron-positron pair, and found to be consistent with the standard model prediction. We use the A{sub FB} measurement to extract the effective weak… more
Date: April 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Search for associated production of charginos and neutralinos in the trilepton final state using 2.3 fb**-1 of data

Description: We report the results of a search for associated production of charginos and neutralinos using a data set corresponding to an integrated luminosity of 2.3 fb{sup -1} collected with the D0 experiment during Run II of the Tevatron proton-antiproton collider. Final states containing three charged leptons and missing transverse energy are probed for a signal from supersymmetry with four dedicated trilepton event selections. No evidence for a signal is observed, and we set limits on the product of p… more
Date: January 1, 2009
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV

Description: We measure the t{bar t} production cross section in p{bar p} collisions at {radical}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{sup -1} of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure {sigma}{sub t{bar t}} = 7.62 {+-} 0.85 pb, assuming the current world average m{sub t} = 172.6 GeV. We compare our cross section measurement with … more
Date: March 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Evidence of WW+WZ production with lepton + jets final states in p anti-p collisions at s**(1/2) = 1.96-TeV

Description: We present the first evidence of WW+WZ production with lepton+jets final states at a hadron collider. The data correspond to 1.07 inverse femtobarns of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider in proton-antiproton collisions at sqrt(s)=1.96 TeV. The observed cross section for WW+WZ production is 20.2 +/- 4.5 pb, consistent with the SM prediction of 16.1 +/- 0.9 pb. The probability for background fluctuations to produce an excess equal to or larger t… more
Date: October 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Search for pair production of second generation scalar leptoquarks

Description: We report on a search for the pair production of second generation scalar leptoquarks (LQ) in p{bar p} collisions at the center of mass energy {radical}s = 1.96TeV using a data set corresponding to an integrated luminosity of 1.0 fb{sup -1} collected with the D0 experiment at the Fermilab Tevatron Collider. Topologies arising from the LQ{ovr LQ} {yields} {mu}q{nu}q and LQ{ovr LQ} {yields} {mu}q{mu}q decay modes are investigated. No excess of data over the standard model prediction is observed a… more
Date: August 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Measurement of differential Z / gamma* + jet + X cross sections in p anti-p collisions at s**(1/2) = 1.96-TeV

Description: We present new measurements of differential cross sections for Z/{gamma}* ({yields} {mu}{mu})+jet+X production in a 1 fb{sup -1} data sample collected with the D0 detector in p{bar p} collisions at {radical}s = 1.96 TeV. Results include the first measurements differential in the Z/{gamma}* transverse momentum and rapidity, as well as new measurements differential in the leading jet transverse momentum and rapidity. Next-to-leading order perturbative QCD predictions are compared to the measureme… more
Date: August 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Measurement of the polarization of the $\Upsilon(1S)$ and $\Upsilon(2S)$ states in $p\bar{p}$ collisions at $\sqrt{s}=$1.96 TeV

Description: We present a study of the polarization of the {Upsilon}(1S) and {Upsilon}(2S) states using a 1.3 fb{sup -1} data sample collected by the D0 experiment in 2002-2006 during Run II of the Fermilab Tevatron Collider. We measure the polarization parameter {alpha} = ({sigma}{sub T} - 2{sigma}{sub L})/({sigma}{sub T} + 2{sigma}{sub L}), where {sigma}{sub T} and {sigma}{sub L} are the transversely and longitudinally polarized components of the production cross section, as a function of the transverse m… more
Date: April 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Search for excited electrons in p anti-p collisions at s**(1/2) = 1.96-TeV

Description: We present the results of a search for the production of an excited state of the electron, e*, in proton-antiproton collisions at {radical}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{sup -1}. We search for e* in the process p{bar p} {yields} e*e, with the e* subsequently decaying to an electron plus photon. No excess above the standard model background is observed. Interpreting ou… more
Date: January 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Search for W-prime Boson Resonances Decaying to a Top Quark and a Bottom Quark

Description: We search for the production of a heavy W{prime} gauge boson that decays to third generation quarks in 0.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, collected with the D0 detector at the Fermilab Tevatron collider. We find no significant excess in the final-state invariant mass distribution and set upper limits on the production cross section times branching fraction. For a left-handed W{prime} boson with SM couplings, we set a lower mass limit of 731 GeV. For right-handed W{p… more
Date: March 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Search for long-lived particles decaying into electron or photon pairs with the D0 detector

Description: In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, like hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quas… more
Date: June 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Simultaneous measurement of the ratio B(t->Wb)/B(t->Wq) and the top quark pair production cross section with the D0 detector at s**(1/2) = 1.96-TeV

Description: The authors present the first simultaneous measurement of the ratio of branching fractions, R = {Beta}(t {yields} Wb)/{Beta}(t {yields} Wq), with q being a d, s, or b quark, and the top quark pair production cross section {sigma}{sub t{bar t}} in the lepton plus jets channel using 0.9 fb{sup -1} of p{bar p} collision data at {radical}s = 1.96 TeV collected with the D0 detector. they extract R and {sigma}{sub t{bar t}} by analyzing samples of events with 0, 1 and {ge} 2 identified b jets. They m… more
Date: January 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Measurement of the B0(s) semileptonic branching ratio to an orbitally excited D**(s) state, Br(B0(s) ---> D-(s1)(2536) mu+ nu X)

Description: In a data sample of approximately 1.3 fb{sup -1} collected with the D0 detector between 2002 and 2006, the orbitally excited charm state D{sub s1}{sup {+-}}(2536) has been observed with a measured mass of 2535.7 {+-} 0.6(stat) {+-} 0.5(syst) MeV/c{sup 2} via the decay mode B{sub s}{sup 0} {yields} D{sub s1}{sup -}(2536){mu}{sup +} {nu}X. A first measurement is made of the branching ratio product Br({bar B} {yields} D{sub s1}{sup -}(2536){mu}{sup +}{nu}X) {center_dot} Br(D{sub s1}{sup -} {yields… more
Date: December 1, 2007
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Measurement of B0(s) mixing parameters from the flavor-tagged decay B0(s) ---> J/psi phi

Description: From an analysis of the flavor-tagged decay B{sub s}{sup 0} {yields} J/{psi}{phi} they obtain the width difference between the B{sub s}{sup 0} light and heavy mass eigenstates, {Delta}{Lambda}{sub s} {triple_bond} {Lambda}{sub L} - {Lambda}{sub H} = 0.19 {+-} 0.07(stat){sub -0.01}{sup +0.02}(syst) ps{sup -1}, and the CP-violating phase, {phi}{sub s} = -0.57{sub -0.30}{sup +0.24}(stat){sub -0.02}{sup +0.07}(syst). The allowed 90% C.L. intervals of {Delta}{Lambda}{sub s} and {phi}{sub s} are 0.06… more
Date: February 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Search for admixture of scalar top quarks in the t anti-t lepton+jets final state at s**(1/2) = 1.96-TeV

Description: A search for pair production of the lightest supersymmetric partner of the top quark, {tilde t}{sub 1}, is performed in the lepton+jets channel using 0.9 fb{sup -1} of data collected by the D0 experiment. Kinematic differences between {tilde t}{sub 1}{bar {tilde t}}{sub 1} and the dominant top quark pair production background are used to separate the two processes. First limits from Run II of the Fermilab Tevatron Collider for the scalar top quark decaying to a chargino and a b quark ({tilde t}… more
Date: January 1, 2009
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen