Study of methods of resolved top quarks kinematic reconstruction in the tt̄→ℓ+jets channel is presented at the particle level as well as the fast-simulation detector level. Previous and current ...pseudo-top quark reconstruction algorithms are compared with suggestions presented on how to improve the reconstructed top-quark mass line shape, including the check of performance on physics observables in terms of correlations between detector, particle and parton levels, and in unfolding, with implications for current high energy physics experiments.
Study of methods of resolved top quarks kinematic reconstruction in the tt̄→ℓ+jets channel is presented at the particle level as well as the fast-simulation detector level. Previous and current ...pseudo-top quark reconstruction algorithms are compared with suggestions presented on how to improve the reconstructed top-quark mass line shape, including the check of performance on physics observables in terms of correlations between detector, particle and parton levels, and in unfolding, with implications for current high energy physics experiments.
We study the top quark pair events production in $pp$ collisions in the
$\ell$+jets channel at the LHC energy of $\sqrt{s} = 14$ TeV for Standard Model
as well as new physics processes. We explore ...the usage of semi-boosted
topologies where the top quark decays into a boosted hadronic $W$-jet and an
isolated $b$-jet and study their performance in the $t\bar{t}$ events kinematic
reconstruction. An efficiency increase is observed and the correlation of
selected kinematic variables between the detector and particle level is
studied. Quality of the reconstructed mass line shape of a $Z'$ model with
applications in current LHC experiments is evaluated. The results of the
unfolding procedure for chosen spectra and an explicit proof of a slight
degradation in the signal significance after the unfolding procedure are
presented using the Fully Bayesian unfolding technique.
We present a measurement of the a production cross section sigma((u) over bar) in p (p) over bar collisions at root s = 1.96 TeV using 5.4 fb(-1) of integrated luminosity collected with the D0 ...detector. We consider final states with at least two jets and two leptons (ee, e mu, mu mu), and events with one jet for the e mu final state as well. The measured cross section is sigma((u) over bar) = 7.36(-0.79)(+0.90)(stat + syst) pb. This result combined with the cross section measurement in the lepton + jets final state yields sigma((u) over bar) = 7.56(-0.56)(+0.63)(stat + syst) pb, which agrees with the standard model expectation. The relative precision of 8% of this measurement is comparable to the precision of the latest theoretical calculations. (C) 2011 Elsevier B.V. All rights reserved.
We present measurements of the inclusive production cross sections of the Upsilon(1S) bottomonium state in p (p) over bar collisions at root s=1.96 TeV. Using the Upsilon(1S)->mu(+)mu(-) decay ...mode for a data sample of 159 +/- 10 pb(-1) collected by the D0 detector at the Fermilab Tevatron collider, we determine the differential cross sections as a function of the Upsilon(1S) transverse momentum for three ranges of the Upsilon(1S) rapidity: 0 <\y(Upsilon)\<= 0.6, 0.6 <\y(Upsilon)\<= 1.2, and 1.2 <\y(Upsilon)\<= 1.8.
We study the top quark pair events production in \(pp\) collisions in the \(\ell\)+jets channel at the LHC energy of \(\sqrt{s} = 14\) TeV for Standard Model as well as new physics processes. We ...explore the usage of semi-boosted topologies where the top quark decays into a boosted hadronic \(W\)-jet and an isolated \(b\)-jet and study their performance in the \(t\bar{t}\) events kinematic reconstruction. An efficiency increase is observed and the correlation of selected kinematic variables between the detector and particle level is studied. Quality of the reconstructed mass line shape of a \(Z'\) model with applications in current LHC experiments is evaluated. The results of the unfolding procedure for chosen spectra and an explicit proof of a slight degradation in the signal significance after the unfolding procedure are presented using the Fully Bayesian unfolding technique.
We present new direct constraints on a general Wtb interaction using data corresponding to an integrated luminosity of 5.4 fb-1 collected by the D0 detector at the Tevatron p p macr collider. The ...standard model provides a purely left-handed vector coupling at the Wtb vertex, while the most general, lowest dimension Lagrangian allows right-handed vector and left- or right-handed tensor couplings as well. We obtain precise limits on these anomalous couplings by comparing the data to the expectations from different assumptions on the Wtb coupling.
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