Search results for "waves"

showing 10 items of 1766 documents

Systematic investigation of the drip-line nuclei 11Li and 14Be and their unbound subsystems 10Li and 13Be

2007

Fragmentation reactions in a carbon target with beams of 11Li and 14Be at relativistic energies have been studied in a kinematically complete experiment at the ALADIN-LAND setup at GSI. Excited states in 11Li and 14Be were obtained from the data in the inelastic channel. The measured cross sections with the core nucleus in the final state show that in the 14Be case core polarization plays an important role. In the one-neutron knockout channels the measured angular correlations between fragment and neutron are asymmetric, which demonstrates the presence of states with different parities in the 11Li and 14Be ground states. For 10Li a low-lying virtual s-state, a p-state and evidence for a d-s…

PhysicsNuclear physicsNuclear and High Energy PhysicsFragmentation (mass spectrometry)Excited stateHalo nucleusNeutronAtomic physicsNuclear ExperimentPolarization (waves)Ground stateNuclear Physics A
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Observation and polarization measurement ofB0→a1(1260)+a1(1260)−decay

2009

We present measurements of the branching fraction B and longitudinal polarization fraction fL for B0→a1(1260)+a1(1260)- decays, with a1(1260)±→π-π+π±. The data sample, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represents 465×106 produced BB pairs. We measure B(B0→a1(1260)+a1(1260)-)×[B(a1(1260)+→π-π+π+)]2= (11.8±2.6±1.6)×10-6 and fL=0.31±0.22±0.10, where the first uncertainty is statistical and the second systematic. The decay mode is measured with a significance of 5.0 standard deviations including systematic uncertainties.

PhysicsNuclear physicsNuclear and High Energy PhysicsParticle decay010308 nuclear & particles physicsBranching fractionElectron–positron annihilation0103 physical sciencesDetector010306 general physicsPolarization (waves)01 natural sciencesStandard deviationPhysical Review D
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Lepton conservation and time reversal in β-decay

1959

It was investigated which conclusions can be inferred from β-decay experiments taking into account experimental errors but without making theoretical assumptions.

PhysicsNuclear physicsNuclear and High Energy PhysicsParticle physicsAstronomy and AstrophysicsParity (physics)NeutrinoPolarization (waves)Beta decayAtomic and Molecular Physics and OpticsLeptonIl Nuovo Cimento
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Leptoproduction of neutrino pairs in the nuclear coulomb field

1985

20 páginas, 6 figuras, 2 tablas.-- PACS. 13.60. - Photon and charged-lepton interactions with hadrons.

PhysicsNuclear physicsParticle physicsHigh Energy Physics::PhenomenologyCoulombHigh Energy Physics::ExperimentStandard theoryNeutrinoPolarization (waves)Lepton
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Polarization Effects in Electromagnetic Deuteron Break-Up

1992

Polarization observables of deuteron photo- and electrodisintegration with polarized photons and electrons, respectively, and oriented deuterons are investigated with respect to their sensitivity to subnuclear degrees of freedom and relativistic effects, to the different electric and magnetic multipole contributions, to various realistic potential models and — in electrodisintegration — to e.m. form factors.

PhysicsNuclear physicsPhotonBreak-UpDeuteriumNuclear TheoryPolarization observablesElectronRelativistic quantum chemistryMultipole expansionPolarization (waves)
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Measurement of the positron longitudinal polarization in muon decay

1981

The longitudinal polarization of the ${e}^{+}$ from ${\ensuremath{\mu}}^{+}$ decay has been measured. The spin dependence of positron-electron (Bhabha) scattering and of annihilation in flight were used as the analyzing reactions. The combined statistical and systematic error was reduced by a factor of approximately 3 below that of any previous measurement. The longitudinal polarization was found to be 1.010\ifmmode\pm\else\textpm\fi{}0.064 (statistical plus systematic error) and to be consistent with the prediction of the $V\ensuremath{-}A$ interaction.

PhysicsNuclear physicsSystematic errorParticle physicsAnnihilationMuonPositronScatteringHigh Energy Physics::ExperimentPolarization (waves)Physical Review D
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Structure and dynamics of sawteeth crashes in ASDEX Upgrade

2010

The crash phase of the sawteeth in ASDEX Upgrade tokamak [Herrmann et al., Fusion Sci. Technol. 44(3), 569 (2003)] is investigated in detail in this paper by means of soft x-ray (SXR) and electron cyclotron emission (ECE) diagnostics. Analysis of precursor and postcursor (1,1) modes shows that the crash does not affect the position of the resonant surface q=1. Our experimental results suggest that sawtooth crash models should contain two ingredients to be consistent with experimental observations: (1) the (1,1) mode structure should survive the crash and (2) the flux changes should be small to preserve the position of the q=1 surface close to its original location. Detailed structure of the…

PhysicsNuclear physicsTokamakASDEX UpgradelawCyclotronPhase (waves)Magnetic reconnectionPlasma diagnosticsSawtooth waveCondensed Matter PhysicsInstabilitylaw.inventionPhysics of Plasmas
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Comment on the Feasibility of Antiproton Polarization in LEAR by Means of the Transverse Stern-Gerlach Effect

1984

The study of polarization effects in nucleon-nucleon scattering experiments has increased considerably our understanding of the Nuclear forces. Correspondingly it can be expected that the study of polarization phenomena in antiproton-nucleon scattering will also help us to resolve — at least partly — the complicated spin structure of the antiproton-nucleon amplitudes.

PhysicsNuclear physicsTransverse planeAmplitudeStern–Gerlach experimentAntiprotonScatteringNuclear TheoryNuclear forceSpin structureNuclear ExperimentPolarization (waves)
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Asymmetries in elastic scattering of 100 MeVπ+from a polarizedHe3target

1991

We report the observation of a large asymmetry in the elastic scattering of 100 MeV {pi}{sup +} from a polarized {sup 3}He target. Measurements have been made at laboratory angles of 60{degree}, 80{degree}, and 100{degree}, with the largest value {ital A}{sub {ital y}}=0.89{plus minus}0.12 occurring at 80{degree}, near a cross-section minimum. This asymmetry is the largest observed to date in pion scattering from a spin-1/2 nucleus. The {ital A}{sub {ital y}} data are qualitatively reproduced by a schematic model; however, agreement with the data is significantly improved when realistic three-body Faddeev wave functions and a full nonlocal distorted-wave impulse approximation reaction model…

PhysicsNuclear reactionElastic scatteringFaddeev equationsScatteringmedia_common.quotation_subjectGeneral Physics and AstronomyPolarization (waves)AsymmetryNuclear physicsPionAtomic physicsWave functionmedia_commonPhysical Review Letters
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Out-of-plane emission of nuclear matter in Au+Au collisions between 100 and 800 AMeV

1997

We present new experimental results concerning the azimuthal distributions of proton-likes, light and intermediate mass fragments at midrapidity for Au(100-800 AMeV)+Au collisions measured with the FOPI phase-I detector at GSI in Darmstadt. The azimuthal distributions are investigated as a function of the collision centrality, the incident energy, the fragment charge and transverse momentum. The azimuthal anisotropy is maximum for impact parameters around 7 fm. Intermediate mass fragments present a stronger out-of-plane emission signal than light fragments and a saturation is reached for Z greater than or equal to 4. The azimuthal anisotropy increases with the fragment transverse momentum a…

PhysicsNuclear reactionNuclear and High Energy PhysicsPhase (waves)Charge (physics)Nuclear matterAzimuthNuclear physicsNuclear Reactions; Au-197 (Au-197; X); E=100-800 MeV/nucleon; Azimuthal anisotropy; Out-of-plane emissionAtomic physicsNuclear ExperimentAnisotropySaturation (magnetic)Beam (structure)Nuclear Physics A
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