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Corcoran, M.

Publications and source records attributed to Corcoran, M..

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Measurement of the asymmetry in angular distributions of leptons produced in dilepton t t ¯ final states in p p ¯ collisions at s = 1.96 TeV

We present measurements of asymmetries in angular distributions of leptons produced in ttbar events in proton-antiproton collisions at the Fermilab Tevatron Collider. We consider final states where the W bosons from top quark and antiquark decays both decay into l nu (l=e, mu) resulting in oppositely charged dilepton final states with accompanying jets. Using 9.7 fb -1 of integrated luminosity collected with the D0 detector, we find the asymmetries in lepton pseudorapidity compatible with predictions based on the standard model.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Search for the Higgs boson in lepton, tau and jets final states

We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with two or more jets using 9.7 fb –1 of Run II Fermilab Tevatron Collider data collected with the D0 detector. The analysis is sensitive to Higgs boson production via gluon fusion, associated vector boson production, and vector boson fusion, followed by the Higgs boson decay to tau lepton pairs or to W boson pairs. The ratios of 95% C.L. upper limits on the cross section times branching ratio to those predicted by the standard model are obtained for orthogonal subsamples that are enriched in either H → ττ decays or H → WW decays, and for the combination of these subsample limits. As a result, the observed and expected limit ratios for the combined subsample at a Higgs boson mass of 125 GeV are 11.3 and 9.0, respectively.

experiment-HEP↗
DOE OSTI2013

Search for a Higgs boson in diphoton final states with the D0 detector in9.6 fb-1ofpp¯collisions ats=1.96 TeV

.We present a search for a Higgs boson decaying into a pair of photons based on 9.6 fb- 1 of $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. The search employs multivariate techniques to discriminate signal from the nonresonant background and is separately optimized for a standard model and a fermiophobic Higgs boson. No significant excess of data above the background prediction is observed and upper limits on the product of the cross section and branching fraction are derived at the 95% confidence level as a function of Higgs boson mass. For a standard model Higgs boson with mass of 125 GeV, the observed (expected) upper limits are a factor of 12.8 (8.7) above the standard model prediction. The existence of a fermiophobic Higgs boson with mass in the 100–113 GeV range is excluded at the 95% confidence level.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Measurement of the differential cross sections for isolated direct photon pair production in $p\bar{p}$ collisions at $\sqrt{s}$= 1.96 TeV

We present measurements of direct photon pair production cross sections using 8.5fb -1 of data collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ collider. The results are presented as differential distributions of the photon pair invariant mass $dσ/dM_{γγ}$, pair transverse momentum $dσ/dp^{γγ}_{T}$, azimuthal angle between the photons $dσ/dΔφ_{γγ}$, and polar scattering angle in the Collins–Soper frame $dσ/d|cos θ*|$. Measurements are performed for isolated photons with transverse momenta $p^γ_T$ > 18(17)GeV for the leading (next-to-leading) photon in $p_T$, pseudorapidities , |$η^γ$| < 0.9 and a separation in η–φ space Δ$\mathscr{R}_{γγ}$ >0.4. We present comparisons with the predictions from Monte Carlo event generators DIPHOX and RESBOS implementing QCD calculations at next-to-leading order, 2γNNLO at next-to-next-to-leading order, and SHERPA using matrix elements with higher-order real emissions matched to parton shower.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Search for anomalous quartic WWγγ couplings in dielectron and missing energy final states in pp̄ collisions at √s=1.96 TeV

We present a search for anomalous components of the quartic gauge boson coupling WWγγ in events with an electron, a positron and missing transverse energy. The analyzed data correspond to 9.7 fb⁻¹ of integrated luminosity collected by the D0 detector in pp̄ collisions at s√=1.96 TeV. The presence of anomalous quartic gauge couplings would manifest itself as an excess of boosted WW events. No such excess is found in the data, and we set the most stringent limits to date on the anomalous coupling parameters a W 0 and a W C . When a form factor with Λ cutoff =0.5 TeV is used, the observed upper limits at 95% C.L. are |a W 0 /Λ²|<0.0025 GeV⁻² and |a W C /Λ²|<0.0092 GeV⁻².

Abazov, V. M.↗
DOE OSTI2013

Measurement of the ratio of differential cross sections σ(pp̄→Z+b jet)/σ(pp̄→Z+jet) in pp̄ collisions at √s=1.96 TeV

We measure the ratio of cross sections, σ(pp̄→Z+b jet)/σ(pp̄→Z+jet), for associated production of a Z boson with at least one jet. The ratio is also measured as a function of the Z boson transverse momentum, jet transverse momentum, jet pseudorapidity, and the azimuthal angle between the Z boson with respect to the highest p T b tagged jet. These measurements use data collected by the D0 experiment in Run II of Fermilab’s Tevatron pp̄ Collider at a center-of-mass energy of 1.96 TeV, and correspond to an integrated luminosity of 9.7 fb⁻¹. The results are compared to predictions from next-to-leading order calculations and various Monte Carlo event generators.

Abazov, V. M.↗
DOE OSTI2013

The D0 Run IIb Luminosity Measurement

An assessment of the recorded integrated luminosity is presented for data collected with the D0 detector at the Fermilab Tevatron Collider from June 2006 to September 2011 (Run IIb). In addition, a measurement of the effective cross section for inelastic interactions, also referred to as the luminosity constant, is reported. This measurement incorporates new features that lead to a substantial improvement in the precision of the result. A luminosity constant of \sigma_{LM} = 48.3\pm1.9\pm0.6 mb is obtained, where the first uncertainty is due to the accuracy of the inelastic cross section used by both CDF and D0, and the second uncertainty is due to D0 sources. The recorded luminosity for the highest E_T jet trigger is L_rec = 9.2 \pm 0.4 fb^{-1}, with a relative uncertainty of 4.3%.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗