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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Primer on nuclear exchange models

Basic physics is applied to nuclear force exchange models between two nations. Ultimately, this scenario approach can be used to try and answer the age old question of 'how much is enough?' This work is based on Chapter 2 of Physics of Societal Issues: Calculations on National Security, Environment and Energy (Springer, 2007 and 2014)

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2021

Study of the normalized transverse momentum distribution of W bosons produced in $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV

We present a study of the normalized transverse momentum distribution of W bosons produced in $p\bar{p}$ collisions, using data corresponding to an integrated luminosity of 4.35 fb -1 collected with the D0 detector at the Fermilab Tevatron collider at $\sqrt{s}$ = 1.96 TeV. The measurement focuses on the transverse momentum region below 15 GeV, which is of special interest for electroweak precision measurements; it relies on the same detector calibration methods which were used for the precision measurement of the W boson mass. The measured distribution is compared to different QCD predictions and a procedure is given to allow the comparison of any further theoretical models to the D0 data.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Up and down quark structure of the proton

We report an improved measurement of the valence u and d quark distributions from the forward-backward asymmetry in the Drell-Yan process using 8.6 fb − 1 of data collected with the D0 detector in p p ¯ collisions at s = 1.96 . This analysis provides the values of new structure parameters that are directly related to the valence up and down quark distributions in the proton. In other experimental results measuring the quark content of the proton, d quark contributions are mixed with those from other quark flavors. In this measurement, the u and d quark contributions are separately extracted by applying a factorization of the QCD and electroweak portions of the forward-backward asymmetry. Published by the American Physical Society 2024

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

Measurement of the WZ and ZZ production cross sections using leptonic final states in 8.6 fb⁻¹ of pp̄ collisions

We study the processes pp̄→WZ→l ± νl⁺l⁻ and pp̄→ZZ→l⁺l⁻νν¯, where l=e or μ. Using 8.6 fb⁻¹ of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron collider, we measure the WZ production cross section to be 4.50 +0.63 –0.66 pb which is consistent with, but slightly larger than, the prediction of the standard model. The ZZ cross section is measured to be 1.64±0.46 pb, in agreement with a prediction of the standard model. Combination with an earlier analysis of the ZZ→l⁺l⁻l⁺l⁻ channel yields a ZZ cross section of 1.44 +0.35 –0.34 pb.

Abazov, V. M.↗
DOE OSTI2012

Search for Zγ events with large missing transverse energy in pp̄ collisions at √s=1.96 TeV

We present the first search for new phenomena in Zγ final states with large missing transverse energy using data corresponding to an integrated luminosity of 6.2 fb⁻¹ collected with the D0 experiment in pp̄ collisions at √s=1.96 TeV. This signature is predicted in gauge-mediated supersymmetry-breaking models, where the lightest neutralino χ˜⁰₁ is the next-to-lightest supersymmetric particle and is produced in pairs, possibly through decay from heavier supersymmetric particles. The χ˜⁰₁ can decay either to a Z boson or a photon and an associated gravitino that escapes detection. We exclude this model at the 95% C.L. for supersymmetry-breaking scales of Λ<87 TeV.

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

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

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↗