Measurement of differential J / ψ production cross sections and forward-backward ratios in p + Pb collisions with the ATLAS detector
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73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
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Results for “section”
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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Measurement of the 169 Tm(n,3n) 167 Tm cross section and the associated branching ratios in the decay of 167 Tm [Measurement of the 169 Tm(n,3n) 167 Tm cross section and the branching ratios in the decay of 167 Tm]
The cross section for the 169 Tm(n,3n) 167 Tm reaction was measured from 17 to 22 MeV using quasimonoenergetic neutrons produced by the 2 H(d,n) 3 He reaction. This energy range was studied to resolve the discrepancy between previous (n,3n) cross-section measurements. In addition, the absolute γ-ray branching ratios following the electron-capture decay of 167 Tm were measured. Furthermore, these results provide more reliable nuclear data for an important diagnostic that is used at the National Ignition Facility to estimate the yield of reaction-in-flight neutrons produced via the inertial-confinement-fusion plasma in deuterium-tritium capsules.
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
Neutrino-Nucleus Cross Section within the Extended Factorization Scheme
The factorization scheme, based on the impulse approximation and the spectral function formalism, has been recently generalized to allow the description of electromagnetic nuclear interactions driven by two-nucleon currents. We have extended this framework to the case of weakly charged and neutral currents, and carried out calculations of the double-differential neutrino-carbon and neutrino-oxygen cross sections using two different models of the target spectral functions. The results, showing a moderate dependence on the input spectral function, confirm that our approach provides a consistent treatment of all reaction mechanisms contributing to the signals detected by accelerator-based neutrino experiments.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Measurement of the differential cross section of photon plus jet production in p(p)over-bar collisions at root s=1.96 TeV
N/A
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Measurements of normalized differential cross sections for t t ¯ production in p p collisions at ( s ) = 7 TeV using the ATLAS detector
We present measurements of normalized differential cross sections for top-quark pair production as a function of the top-quark transverse momentum, and of the mass, transverse momentum, and rapidity of the $t\bar{t}$ system, in proton–proton collisions at a center-of-mass energy of √ s=7 TeV. The data set corresponds to an integrated luminosity of 4.6 fb ₋1 , recorded in 2011 with the ATLAS detector at the CERN Large Hadron Collider. Events are selected in the lepton + jets channel, requiring exactly one lepton and at least four jets with at least one of the jets tagged as originating from a b-quark. The measured spectra are corrected for detector efficiency and resolution effects and are compared to several Monte Carlo simulations and theory calculations. The results are in fair agreement with the predictions in a wide kinematic range. Nevertheless, data distributions are softer than predicted for higher values of the mass of the $t\bar{t}$ system and of the top-quark transverse momentum. Lastly, the measurements can also discriminate among different sets of parton distribution functions.
43 PARTICLE ACCELERATORS↗
Cross sections for the reactions e + e - → K S 0 K L 0 π 0 , K S 0 K L 0 η , and K S 0 K L 0 π 0 π 0 from events with initial-state radiation
Here, we study the processes e + e - → K$0\atop{S}$ K$0\atop{L}$ π 0 γ , K $0\atop{S}$ K$0\atop{L}$ η γ , and K$0\atop{S}$ K$0\atop{L}$ π 0 π 0 γ , where the photon is radiated from the initial state, providing cross section measurements for the hadronic final states over a continuum of center-of-mass energies. The results are based on 469 fb -1 of data collected at or near the Υ ( 4 S ) resonance with the BABAR detector at SLAC. We present the first measurements of the e + e - → K$0\atop{S}$ K$0\atop{L}$ π 0 , K$0\atop{S}$ K$0\atop{L}$ η , and K$0\atop{S}$ K$0\atop{L}$ π 0 π 0 cross sections up to a center-of-mass energy of 4 GeV and study their intermediate resonance structures. We observe J / ψ decays to all of these final states for the first time, present measurements of their J / ψ branching fractions, and search for ψ (2S) decays.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Measurement of the ZZ Production Cross Section in $pp$ Collisions at $\sqrt{s}$ = 13 TeV with the ATLAS Detector
The ZZ production cross section in proton-proton collisions at 13 TeV center-of-mass energy is measured using 3.2 fb$^{-1}$ of data recorded with the ATLAS detector at the Large Hadron Collider. The considered Z boson candidates decay to an electron or muon pair of mass 66-116 GeV. The cross section is measured in a fiducial phase space reflecting the detector acceptance. It is also extrapolated to a total phase space for Z bosons in the same mass range and of all decay modes, giving $16.7^{+2.2}_{-2.0}$(stat)$ ^{+0.9}_{-0.7}$(syst)$ ^{+1.0}_{-0.7}$(lumi) pb. The results agree with standard model predictions.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
A measurement of the ratio of the production cross sections for W and Z bosons in association with jets with the ATLAS detector
In this study, the ratio of the production cross sections for W and Z bosons in association with jets has been measured in proton–proton collisions at √s = 7TeV with the ATLAS experiment at the Large Hadron Collider. The measurement is based on the entire 2011 dataset, corresponding to an integrated luminosity of 4.6fb –1 . Inclusive and differential cross-section ratios for massive vector bosons decaying to electrons and muons are measured in association with jets with transverse momentum p T > 30GeV and jet rapidity |y| < 4.4. The measurements are compared to next-to-leading-order perturbative QCD calculations and to predictions from different Monte Carlo generators implementing leading-order matrix elements supplemented by parton showers.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Measurement of the cross-section and charge asymmetry of W bosons produced in proton–proton collisions at $\sqrt{s}=8~\text {TeV}$ with the ATLAS detector
This paper presents measurements of the W + → μ + ν and W - → μ-ν cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton–proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2 fb -1 . The precision of the cross-section measurements varies between 0.8 and 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Interaction energies, charge exchange cross sections, and diffusion cross sections for n plus -n and 0 plus -0 collisions
Interaction energies, charge exchange cross sections, & diffusion cross sections for collisions of atoms of nitrogen & oxygen with corresponding positive ions
CHARGE EXCHANGE↗
Comparison of numerical capture cross sections with experimental reaction cross sections for NH3/+/ + NH3
Comparing numerically calculated capture cross sections with experimental reaction cross sections for NH3/+/ + NH3
Dugan, J. V., Jr.↗
Data Processor Having Multiple Sections Activated at Different Times by Selective Power Coupling to the Sections Patent
Data processor having multiple sections activated at different times by selective power coupling to sections
Cliff, R. A.↗
Optimal one-section and two-section circular sound-absorbing duct liners for plane-wave and monopole sources without flow
A discrete frequency study is made of the influence of source characteristics on the optimal properties of acoustically lined uniform and two section ducts. Two simplified sources, a plane wave and a monopole, are considered in some detail and over a greater frequency range than has been previously studied. Source and termination impedance effects are given limited examination. An example of a turbomachinery source and three associated source variants is also presented. Optimal liner designs based on modal theory approach the Cremer criterion at low frequencies and the geometric acoustics limit at high frequencies. Over an intermediate frequency range, optimal two section liners produced higher transmission losses than did the uniform configurations. Source distribution effects were found to have a significant effect on optimal liner design, but source and termination impedance effects appear to be relatively unimportant.
Lester, H. C.↗
A flight investigation of blade section aerodynamics for a helicopter main rotor having NLR-1T airfoil sections
A flight investigation was conducted using a teetering-rotor AH-1G helicopter to obtain data on the aerodynamic behavior of main-rotor blades with the NLR-1T blade section. The data system recorded blade-section aerodynamic pressures at 90 percent rotor radius as well as vehicle flight state, performance, and loads. The test envelope included hover, forward flight, and collective-fixed maneuvers. Data were obtained on apparent blade-vortex interactions, negative lift on the advancing blade in high-speed flight and wake interactions in hover. In many cases, good agreement was achieved between chordwise pressure distributions predicted by airfoil theory and flight data with no apparent indications of blade-vortex interactions.
Morris, C. E. K., Jr.↗
Accurate universal parameterization of absorption cross sections II--neutron absorption cross sections
A recent parameterization (here after referred as paper I, Ref. [4]) of absorption cross sections for any system of charged ions collisions including proton -nucleus collisions, is extended for neutron-nucleus collisions valid from approximately 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pair (charged and/or uncharged). The parameters are associated with the physics of the problem. At lower energies, the optical potential at the surface is important and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.
NASA Discipline Radiation Health↗
The hydrogen molecule under the reaction microscope: single photon double ionization at maximum cross section and threshold (doubly differential cross sections)
In this paper, we studied the photo double ionization of hydrogen molecules in the threshold region (50 eV) and the complete photo fragmentation of deuterium molecules at maximum cross section (75 eV) with single photons (linearly polarized) from the Advanced Light Source, using the reaction microscope imaging technique. The 3D-momentum vectors of two recoiling ions and up to two electrons were measured in coincidence. We present the kinetic energy sharing between the electrons and ions, the relative electron momenta, the azimuthal and polar angular distributions of the electrons in the body-fixed frame. We also present the dependency of the kinetic energy release in the Coulomb explosion of the two nuclei on the electron emission patterns. We find that the electronic emission in the body-fixed frame is strongly influenced by the orientation of the molecular axis to the polarization vector and the internuclear distance as well as the electronic energy sharing. Finally, traces of a possible breakdown of the Born–Oppenheimer approximation are observed near threshold.
74 ATOMIC AND MOLECULAR PHYSICS↗
Measurement of the production cross section of prompt J/ψ mesons in association with a W ± boson in pp collisions at $ \sqrt{s} $ = 7 TeV with the ATLAS detector
The process pp → W ± J/ψ provides a powerful probe of the production mechanism of charmonium in hadronic collisions, and is also sensitive to multiple parton interactions in the colliding protons. Using the 2011 ATLAS dataset of 4.5 fb -1 of $ \sqrt{s} $ = 7 TeV pp collisions at the LHC, the first observation is made of the production of W ± + prompt J/ψ events in hadronic collisions, using W ± → μν μ and J/ψ → μ + μ - . A yield of 27.4$ ^{+7.5} _{-6.5} $ W ± + prompt J/ψ events is observed, with a statistical significance of 5.1σ. The production rate as a ratio to the inclusive W ± boson production rate is measured, and the double parton scattering contribution to the cross section is estimated.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Measurement of the production cross-section of psi(2S) - greater than J/psi(- greater than mu(+)mu(-))pi(+) pi(-) in pp collisions at root s=7 TeV at ATLAS
N/A
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗