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Results for “deterrence”

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 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 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.↗