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V M Abazov,
B Abbott,
M Abolins,
B S Acharya,
M Adams,
T Adams,
E Aguilo,
M Ahsan,
G D Alexeev,
G Alkhazov, [......],
C Zeitnitz,
S Zelitch,
T Zhao,
B Zhou,
J Zhu,
M Zielinski,
D Zieminska,
L Zivkovic,
V Zutshi,
E G Zverev
[show abstract]
[hide abstract]
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.
Physical Review Letters 04/2009; 102(9):092002. · 7.37 Impact Factor
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V M Abazov,
B Abbott,
M Abolins,
B S Acharya,
M Adams,
T Adams,
E Aguilo,
M Ahsan,
G D Alexeev,
G Alkhazov, [......],
S Zelitch,
T Zhao,
B Zhou,
J Zhu,
M Zielinski,
D Zieminska,
A Zieminski,
L Zivkovic,
V Zutshi,
E G Zverev
[show abstract]
[hide abstract]
ABSTRACT: We measure the mass of the top quark using top-quark pair candidate events in the lepton+jets channel from data corresponding to 1 fb;{-1} of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron collider. We use a likelihood technique that reduces the jet energy scale uncertainty by combining an in situ jet energy calibration with the independent constraint on the jet energy scale (JES) from the calibration derived using photon+jets and dijet samples. We find the mass of the top quark to be 171.5+/-1.8(stat.+JES)+/-1.1(syst.) GeV.
Physical Review Letters 11/2008; 101(18):182001. · 7.37 Impact Factor
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V M Abazov,
B Abbott,
M Abolins,
B S Acharya,
M Adams,
T Adams,
E Aguilo,
S H Ahn,
M Ahsan,
G D Alexeev, [......],
C Zeitnitz,
T Zhao,
B Zhou,
J Zhu,
M Zielinski,
D Zieminska,
A Zieminski,
L Zivkovic,
V Zutshi,
E G Zverev
[show abstract]
[hide abstract]
ABSTRACT: We present a study of the polarization of the Upsilon(1S) and Upsilon(2S) states using a 1.3 fb;{-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_{T}-2sigma_{L})/(sigma_{T}+2sigma_{L}), where sigma_{T} and sigma_{L} are the transversely and longitudinally polarized components of the production cross section, as a function of the transverse momentum (p_{T};{Upsilon}) for the Upsilon(1S) and Upsilon(2S). Significant p_{T};{Upsilon}-dependent longitudinal polarization is observed for the Upsilon(1S). A comparison with theoretical models is presented.
Physical Review Letters 11/2008; 101(18):182004. · 7.37 Impact Factor
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V M Abazov,
B Abbott,
M Abolins,
B S Acharya,
M Adams,
T Adams,
E Aguilo,
M Ahsan,
G D Alexeev,
G Alkhazov, [......],
S Zelitch,
T Zhao,
B Zhou,
J Zhu,
M Zielinski,
D Zieminska,
A Zieminski,
L Zivkovic,
V Zutshi,
E G Zverev
[show abstract]
[hide abstract]
ABSTRACT: We present an observation for ZZ-->l+l-l'+l'- (l, l'=e or mu) production in p[over]p collisions at a center-of-mass energy of sqrt[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(+0.03)_(-0.02) 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- nu[over]nu, yields a significance of 5.7 standard deviations and a combined cross section of sigma(ZZ)=1.60+/-0.63(stat)+0.16_-0.17(syst) pb.
Physical Review Letters 10/2008; 101(17):171803. · 7.37 Impact Factor
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V M Abazov,
B Abbott,
M Abolins,
B S Acharya,
M Adams,
T Adams,
E Aguilo,
S H Ahn,
M Ahsan,
G D Alexeev, [......],
C Zeitnitz,
T Zhao,
B Zhou,
J Zhu,
M Zielinski,
D Zieminska,
A Zieminski,
L Zivkovic,
V Zutshi,
E G Zverev
[show abstract]
[hide abstract]
ABSTRACT: We present a search for the production of neutral Higgs bosons varphi decaying into tau+tau - final states in pp over 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.
Physical Review Letters 09/2008; 101(7):071804. · 7.37 Impact Factor
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B Abbott,
P Baringer,
T Bolton,
Z Greenwood,
E Gregores,
H Kim,
C. Leangsuksun,
D. Meyer,
N. Mondal, S Novaes,
B Quinn,
H Severini,
P Skubic,
J Snow,
M Sosebee,
J Yu
[show abstract]
[hide abstract]
ABSTRACT: The D0 experiment at Fermilab's Tevatron will record several petabytes of data over the next five years in pursuing the goals of understanding nature and searching for the origin of mass. Computing resources required to analyze these data far exceed capabilities of any one institution. Moreover, the widely scattered geographical distribution of D0 collaborators poses further serious difficulties for optimal use of human and computing resources. These difficulties will exacerbate in future high energy physics experiments, like the LHC. The computing grid has long been recognized as a solution to these problems. This technology is being made a more immediate reality to end users in D0 by developing a grid in the D0 Southern Analysis Region (D0SAR), D0SAR-Grid, using all available resources within it and a home-grown local task manager, McFarm. We will present the architecture in which the D0SAR-Grid is implemented, the use of technology and the functionality of the grid, and the experience from operating the grid in simulation, reprocessing and data analyses for a currently running HEP experiment. Comment: 3 pages, no figures, conference proceedings of DPF04 talk
01/2005;
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CMS Collaboration,
V Khachatryan,
A. Sirunyan,
A Tumasyan,
W Adam,
T Bergauer,
M Dragicevic,
J Erö,
C Fabjan,
M Friedl, [......],
J Leonard,
D Lomidze,
R Loveless,
A Mohapatra,
D Reeder,
I Ross,
A Savin,
W Smith,
J Swanson,
M Weinberg
