SwePub - search: WFRF:(Sanghi B.)

Enumeration	Reference	Cover	Find
1.	Aaltonen, T., et al. (author) Combination of Tevatron Searches for the Standard Model Higgs Boson in the W+W- Decay Mode 2010 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:6, s. 061802- Journal article (peer-reviewed)abstract We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb(-1) of p (p) over bar collisions at root s = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard model Higgs boson in the mass range 162-166 GeV at the 95% C.L.
2.	Aaltonen, T., et al. (author) Combination of CDF and D0 measurements of the W boson helicity in top quark decays 2012 In: Physical Review D. - 1550-7998 .- 1550-2368. ; 85:7, s. 071106- Journal article (peer-reviewed)abstract We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7-5.4 fb(-1) of p (p) over bar collisions collected during Run II of the Fermilab Tevatron collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f(0)) and right-handed (f(+)) helicities, we find f(0) = 0.722 +/- 0.081[+/- 0.062(stat) +/- 0.052(syst)] and f(+) = -0.033 +/- 0.046[+/- 0.034(stat) +/- 0.031(syst)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f(0) = 0.682 +/- 0.057[+/- 0.035(stat) +/- 0.046(syst)] for fixed f(+) and f(+) = -0.015 +/- 0.035[+/- 0.018(stat) +/- 0.030(syst)] for fixed f(0). The results are consistent with standard model expectations.
3.	Abazov, V. M., et al. (author) Evidence for the Decay B-s(0)->(DsDs())-D-() and a Measurement of Delta Gamma(CP)(s)/Gamma(s) 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:9, s. 091801- Journal article (peer-reviewed)abstract We search for the semi-inclusive process B-s(0)->(DsDs())-D-() using 2.8 fb(-1) of pp collisions at s=1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe 26.6 +/- 8.4 signal events with a significance above background of 3.2 standard deviations yielding a branching ratio of B(B-s(0)->(DsDs())-D-())=0.035 +/- 0.010(stat.)+/- 0.011(syst.). Under certain theoretical assumptions, these double-charm final states saturate CP-even eigenstates in the B-s(0) decays resulting in a width difference of Delta Gamma(CP)(s)/Gamma(s)=0.072 +/- 0.021(stat.)+/- 0.022(syst.).
4.	Abazov, V. M., et al. (author) Measurement of sigma(p(p)over-bar -> Z plus X)Br(Z -> tau(+)tau(-)) at root s=1.96 TeV 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 670:4-5, s. 292-299 Journal article (peer-reviewed)abstract We present a measurement of the cross section for Z boson production times the branching fraction to tau lepton pairs sigma(p (p) over bar -> Z + X)Br(Z -> tau(+)tau(-)) in p (p) over bar collisions at root s = 1.96 TeV. The measurement is performed in the channel in which one tau lepton decays into a muon and neutrinos. and the other tau lepton decays hadronically or into an electron and neutrinos. The data sample corresponds to an integrated luminosity of 1.0 fb(-1) collected with the DO detector at the Fermilab Tevatron Collider. The sample contains 1511 candidate events with an estimated 20% background from jets or muons misidentified as tau leptons. We obtain sigma . Br = 240 +/- 8 (star) +/- 12 (sys) +/- 15 (lum) pb, which is consistent with the standard model prediction.
5.	Abazov, V. M., et al. (author) Measurement of the Angular and Lifetime Parameters of the Decays B-d(0) -> J/psi K(0) and B-s(0) -> J/psi phi 2009 In:* Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:3, s. 032001-:102, s. 032001- Journal article (peer-reviewed)abstract We present measurements of the linear polarization amplitudes and the strong relative phases that describe the flavor-untagged decays B-d(0) --> J/psi K(0) and B-s(0) --> J/psi phi in the transversity basis. We also measure the mean lifetime (tau) over bar (s) of the B-s(0) mass eigenstates and the lifetime ratio (tau) over bar (s)/tau(d). The analyses are based on approximately 2.8 fb(-1) of data recorded with the D0 detector. From our measurements of the angular parameters we conclude that there is no evidence for a deviation from flavor SU( 3) symmetry for these decays and that the factorization assumption is not valid for the B-d(0) --> J/psi K(0) decay.
6.	Abazov, V. M., et al. (author) Measurement of the differential cross section for the production of an isolated photon with associated jet in p(p)over-bar collisions at root s=1.96 TeV 2008 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 666:5, s. 435-445 Journal article (peer-reviewed)abstract The process p (p) over bar -> gamma + jet + X is studied using 1.0 fb(-1) of data collected by the DO detector at the Fermilab Tevatron p (p) over bar collider at a center-of-mass energy root s = 1.96 TeV. Photons are reconstructed in the central rapidity region vertical bar y(gamma)vertical bar < 1.0 with transverse momenta in the range 30 < p(T)(gamma) < 400 GeV while jets are reconstructed in either the central vertical bar y(jet)vertical bar < 0.8 or forward 1.5 < vertical bar y(jet)vertical bar < 2.5 rapidity intervals with P-T(jet) > 15 GeV. The differential cross section d(3 sigma)/dp(T)(gamma) dy(gamma) dy(jet) is measured as a function of p(T)(gamma) in four regions, differing by the relative orientations of the photon and the jet in rapidity. Ratios between the differential cross sections in each region are also presented. Next-to-leading order QCD predictions using different parameterizations of parton distribution functions and theoretical scale choices are compared to the data. The predictions do not simultaneously describe the measured normalization and p(T)(gamma) dependence of the cross section in the four measured regions.
7.	Abazov, V. M., et al. (author) Observation of ZZ Production in p(p)over-bar Collisions at root s=1.96 TeV 2008 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:17, s. 171803-:101, s. 171803- Journal article (peer-reviewed)abstract We present an observation for ZZ -> l(+) l(-) l'(+) l'(-) (l, l' =e or mu) production in p (p) over bar collisions at a center-of-mass energy of root s = 1.96 TeV. Using 1.7 fb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider, we observe three candidate events with an expected background of 0.14(-0.02)(+0.03) events. The significance of this observation is 5.3 standard deviations. The combination of D0 results in this channel, as well as in ZZ -> l(+) l(-) v (v) over bar yields a significance of 5.7 standard deviations and a combined cross section of sigma(ZZ) = 1.60 +/- 0.63(stat)(-0.17)(+0.16)(syst) pb.
8.	Abazov, V. M., et al. (author) Search for a scalar or vector particle decaying into Z gamma in p(p)over-bar collisions at root s=1.96 TeV 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 671:3, s. 349-355 Journal article (peer-reviewed)abstract We present a search for a narrow scalar or vector resonance decaying into Z gamma with a subsequent Z boson decay into a pair of electrons or moons. The data for this search were collected with the D circle divide detecror at the Fermilab Tevatron p (p) over bar collider at a center of mass energy root s = 1.96 TeV. Using 1.1 (1.0) fb(-1) of data, we observe 49 (50) candidate events in the electron (muon) channel, in good agreement with the standard model prediction. From the combination of both channels, we derive 95% C.L. upper limits on the cross section times branching fraction (sigma x B) into Z gamma. These limits range from 0.19 (0.20) pb for a scalar (vector) resonance mass of 600 GeV/c(2) to 2.5 (3.1) pb for a mass of 140 GeV/c(2).
9.	Abazov, V. M., et al. (author) Search for Associated W and Higgs Boson Production in p(p)over-bar Collisions at root s=1.96 TeV 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 051803-:102, s. 051803- Journal article (peer-reviewed)abstract We present results of a search for WH -> l nu b (b) over bar production in p (p) over bar collisions based on the analysis of 1.05 fb(-1) of data collected by the D0 experiment at the Fermilab Tevatron, using a neural network for separating the signal from backgrounds. No signal-like excess is observed, and we set 95% C. L. upper limits on the WH production cross section multiplied by the branching ratio for H -> b (b) over bar for Higgs boson masses between 100 and 150 GeV. For a mass of 115 GeV, we obtain an observed (expected) limit of 1.5 (1.4) pb, a factor of 11.4 (10.7) times larger than the standard model prediction.
10.	Abazov, V. M., et al. (author) Search for Large Extra Spatial Dimensions in the Dielectron and Diphoton Channels in p(p)over-bar Collisions at root s=1.96 TeV 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 051601-:102, s. 051601- Journal article (peer-reviewed)abstract We report on a search for large extra spatial dimensions in the dielectron and diphoton channels using a data sample of 1: 05 fb(-1) of p (p) over bar collisions at a center-of-mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. The invariant mass spectrum of the data agrees well with the prediction of the standard model. We find the most restrictive 95% C. L. lower limits on the effective Planck scale between 2.1 and 1.3 TeV for 2 to 7 extra dimensions.
11.	Abazov, V. M., et al. (author) Search for Neutral Higgs Bosons at High tan beta in the b(h/H/A) -> b tau(+)tau(-) Channel 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 051804-:102, s. 051804- Journal article (peer-reviewed)abstract The first search in p (p) over bar collisions at root s = 1.96 TeV for the production of neutral Higgs bosons in association with bottom quarks and decaying in two tau leptons is presented. The cross section for this process is enhanced in many extensions of the standard model, such as its minimal supersymmetric extension (MSSM) at large tan beta. The data, corresponding to an integrated luminosity of 328 pb(-1), were collected with the D0 detector at the Fermilab Tevatron Collider. An upper limit is set on the production cross section of neutral Higgs bosons in the mass range of 90 to 150 GeV, and this limit is used to exclude part of the MSSM parameter space.
12.	Abazov, V. M., et al. (author) Search for pair production of second generation scalar leptoquarks 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 671:2, s. 224-232 Journal article (peer-reviewed)abstract We report on a search for the pair production of second generation scalar leptoquarks (LQ) in p (p) over bar collisions at the center of mass energy root s- = 1.96 TeV using a data set corresponding to an integrated luminosity of 1.0 fb(-1) collected with the D empty set experiment at the Fermilab Tevatron Collider. Topologies arising from the LQ (LQ) over bar -> mu q nu q and LQ (LQ) over bar -> mu q mu q decay modes are investigated. No excess of data over the standard model prediction is observed and upper limits on the leptoquark pair production cross section are derived at the 95% C.L. as a function of the leptoquark mass and the branching fraction beta for the decay LQ -> mu q. These are interpreted as lower limits on the leptoquark mass as a function of beta. For beta = 1 (0.5), scalar second generation leptoquarks with masses up to 316 GeV (270 GeV) are excluded.
13.	Abazov, V. M., et al. (author) Search for Anomalous Top-Quark Couplings with the D0 Detector 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:9, s. 092002- Journal article (peer-reviewed)abstract Anomalous Wtb couplings modify the angular correlations of the top-quark decay products and change the single top-quark production cross section. We present limits on anomalous top-quark couplings by combining information from W boson helicity measurements in top-quark decays and anomalous coupling searches in the single top-quark final state. We set limits on right-handed vector couplings as well as left-handed and right-handed tensor couplings based on about 1 fb(-1) of data collected by the D0 experiment.
14.	Abazov, V. M., et al. (author) Search for Higgs bosons decaying to tau pairs in p(p)over-bar collisions with the D0 detector 2008 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:7, s. 071804-:101, s. 071804- Journal article (peer-reviewed)abstract We present a search for the production of neutral Higgs bosons phi decaying into tau(+)tau(-) final states in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV. The data, corresponding to an integrated luminosity of approximately 1 fb(-1), were collected by the D0 experiment at the Fermilab Tevatron Collider. Limits on the production cross section times branching ratio are set. The results are interpreted in the minimal supersymmetric standard model yielding limits that are the most stringent to date at hadron colliders.
15.	Abazov, M, et al. (author) Search for admixture of scalar top quarks in the t(t)over-bar lepton + jets final state at root s=1.96 TeV 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 674:1, s. 4-10 Journal article (peer-reviewed)abstract A search for pair production of the lightest supersymmetric partner of the top quark, (t) over tilde (1), is performed in the lepton + jets channel using 0.9 fb(-1) of data collected by the D circle divide experiment. Kinematic differences between (t) over tilde (1)(t) over tilde (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 ((t) over tilde1 -> (chi) over tilde (+)(1)b) are obtained for scalar top quark masses of 130-190 GeV and chargino masses of 90-150 GeV.
16.	Abazov, V. M., et al. (author) Search for CP violation in B-s(0) -> mu(+) D-s(-) X decays in p(p)over-bar collisions at root s=1.96 TeV 2010 In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 82:1, s. 012003- Journal article (peer-reviewed)abstract We have performed a search for CP violation in a sample of B-s(0) -> mu+Ds-X decays corresponding to 5 fb(-1) of proton-antiproton collisions collected by the D0 detector in Run II at the Fermilab Tevatron Collider. New physics in B-s(0) mixing could contribute a significant CP violating weak phase, which would be observed as a difference in the decay-time distribution for B-s(0) -> (B) over bar (0)(s) oscillated states versus that for (B) over bar (0)(s) -> B-s(0). A fit to the decay-time distributions of the B-s(0)/(B) over bar (0)(s) candidates yields the flavor-specific asymmetry as a(fs)(s) = [-1.7 +/- 9.1(stat)(-1.5)(+1.4)(syst) x 10(-3), which excludes CP violation due to new physics within the experimental sensitivity.
17.	Abazov, M, et al. (author) Measurement of differential Z/gamma* plus jet plus X cross sections in p(p)over-bar collisions at root S=1.96 TeV 2008 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 669:5, s. 278-286 Journal article (peer-reviewed)abstract We present new measurements of differential cross sections for Z/gamma* (-> mu mu) + jet + X production in a 1 fb(-1) data sample collected with the DO detector in p (p) over bar collisions at root 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 measurements, and reasonable agreement is observed, except in the region of low Z/gamma* transverse momentum. Predictions from two event generators based on matrix elements and parton showers, and one pure parton shower event generator are also compared to the measurements. These show significant overall normalization differences to the data and have varied success in describing the shape of the distributions.
18.	Abazov, M, et al. (author) Measurement of gamma + b + X and gamma + c + X Production Cross Sections in pp > Collisions at s=1.96 TeV 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:19, s. 192002- Journal article (peer-reviewed)abstract First measurements of the differential cross sections d(3)sigma/(dp(T)(gamma)dy(gamma)dy(jet)) for the inclusive production of a photon in association with a heavy quark (b, c) jet are presented, covering photon transverse momenta 30 < p(T)(gamma)< 150 GeV, photon rapidities \|y(gamma)\|< 1.0, jet rapidities \|y(jet)\|< 0.8, and jet transverse momenta p(T)(jet)> 15 GeV. The results are based on an integrated luminosity of 1 fb(-1) in pp collisions at s=1.96 TeV recorded with the D0 detector at the Fermilab Tevatron Collider. The results are compared with next-to-leading order perturbative QCD predictions.
19.	Abazov, M, et al. (author) Measurement of the t(t)over-bar production cross section and top quark mass extraction using dilepton events in p(p)over-bar collisions 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 679:3, s. 177-185 Journal article (peer-reviewed)abstract We present a measurement of the top quark pair production cross section in p (p) over bar collisions at root s = 1.96 TeV using approximately 1 fb(-1) collected with the DO detector. We consider decay channels containing two high p(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(-1.0)(+1.0)(stat)(-0.6)(+0.7)(syst)(-0.5)(+0.6)(lumi) pb. Using l tau events only, we measure: sigma(t (t) over bar) x B(t (t) over bar -> l tau b (b) over bar) = 0.13(-0.08)(+0.09)(stat)(-0.06)(+0.06)(syst)(-0.02)(+0.02)(lumi) pb. Comparing the measured cross section as a function of the mass of the top quark with a partial next-to-next-to leading order Quantum Chroniodynamics theoretical prediction, we extract a mass of the top quark of 171.5(-8.8)(+9-9) GeV, in agreement with direct measurements.
20.	Abazov, M, et al. (author) Search for associated production of charginos and neutralinos in the trilepton final state using 2.3 fb(-1) of data 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 680:1, s. 34-43 Journal article (peer-reviewed)abstract 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(-1) collected with the Demptyset 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 production cross section and leptonic branching fraction. Within minimal supergravity, these limits translate into bounds on m(0) and m(1/2) that are well beyond existing limits.
21.	Abazov, M, et al. (author) Search for Resonant Diphoton Production with the D0 Detector 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:23, s. 231801- Journal article (peer-reviewed)abstract We present a search for a narrow resonance in the inclusive diphoton final state using similar to 2.7 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron p (p) over bar Collider. We observe good agreement between the data and the background prediction, and set the first 95% C. L. upper limits on the production cross section times the branching ratio for decay into a pair of photons for resonance masses between 100 and 150 GeV. This search is also interpreted in the context of several models of electroweak symmetry breaking with a Higgs boson decaying into two photons.
22.	Abazov, M, et al. (author) Search for the Standard Model Higgs Boson in the Missing Energy and Acoplanar b-Jet Topology at root s=1.96 TeV 2008 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:25, s. 251802- Journal article (peer-reviewed)abstract We report a search for the standard model Higgs boson in the missing energy and acoplanar b-jet topology, using an integrated luminosity of 0.93 fb(-1) recorded by the D0 detector at the Fermilab Tevatron p (p) over bar Collider. The analysis includes signal contributions from p (p) over bar -> ZH -> v (v) over barb (b) over bar, as well as from WH production in which the charged lepton from the W boson decay is undetected. Neural networks are used to separate signal from background. In the absence of a signal, we set limits on sigma(p (p) over bar -> VH) x B(H -> b (b) over bar) at the 95% C.L. of 2.6-2.3 pb, for Higgs boson masses in the range 105-135 GeV, where V W, Z. The corresponding expected limits range from 2.8 to 2.0 pb.
23.	Abazov, M, et al. (author) Search for Third Generation Scalar Leptoquarks Decaying into tau b 2008 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:24, s. 241802-:101, s. 241802- Journal article (peer-reviewed)abstract We have searched for third generation leptoquarks (LQ(3)) using 1.05 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider operating at s=1.96 TeV. We set a 95% C.L. lower limit of 210 GeV on the mass of a scalar LQ(3) state decaying solely to a b quark and a tau lepton.
24.	Abazov, V. M., et al. (author) Measurement of the Lifetime of the B-c(+/-) Meson in the Semileptonic Decay Channel 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:9, s. 092001- Journal article (peer-reviewed)abstract Using approximately 1.3 fb(-1) of data collected by the D0 detector between 2002 and 2006, we measure the lifetime of the B-c(+/-) meson in the B-c(+/-)-> J/psi mu(+/-)+X final state. A simultaneous unbinned likelihood fit to the J/psi+mu invariant mass and lifetime distributions yields a signal of 881 +/- 80(stat) candidates and a lifetime measurement of tau(B-c(+/-))=0.448(-0.036)(+0.038)(stat)+/- 0.032(syst) ps.
25.	Abazov, M, et al. (author) Evidence of WW and WZ Production with lepton plus jets Final States in pp Collisions at root s=1.96 TeV 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:16, s. 161801- Journal article (peer-reviewed)abstract We present first evidence for WW+WZ production in lepton+jets final states at a hadron collider. The data correspond to 1.07 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron in pp collisions at root s=1.96 TeV. The observed cross section for WW+WZ production is 20.2 +/- 4.5 pb, consistent with the standard model and more precise than previous measurements in fully leptonic final states. The probability that background fluctuations alone produce this excess is < 5.4x10(-6), which corresponds to a significance of 4.4 standard deviations.

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