4,816 research outputs found
Neutral kaon photoproduction on the deuteron
Neutral kaon photoproduction on the deuteron has been investigated by
including the final state effects and compared with the experimental data.
Comparison shows that the models used in this calculation can reproduce the
data in the channel regions fairly well but still give over
predictions in the channel. It seems that the tensor target
asymmetries are more suitable for studying the final state effects. The
extractions of the elementary photoproduction amplitude are also demonstrated.Comment: 6 pages, 6 figures, talk given by A. Salam at Fourth Asia-Pacific
Conference on Few-Body Problems in Physics 2008 (APFB08), Depok, Indonesia,
August 19-23, 200
Magnetic-Field-Induced Mott Transition in a Quasi-Two-Dimensional Organic Conductor
We investigated the effect of magnetic field on the highly correlated metal
near the Mott transition in the quasi-two-dimensional layered organic
conductor, -(BEDT-TTF)Cu[N(CN)]Cl, by the resistance
measurements under control of temperature, pressure, and magnetic field. It was
demonstrated that the marginal metallic phase near the Mott transition is
susceptible to the field-induced localization transition of the first order, as
was predicted theoretically. The thermodynamic consideration of the present
results gives a conceptual pressure-field phase diagram of the Mott transition
at low temperatures.Comment: 4 pages, 4 figure
FE analysis on tube hydroforming of small diametr ZM21 magnesium alloy tube
Tube hydroforming (THF) is one of the plasticity processing methods. Tubular parts, for instance automotive components are expanded by forces such as internal pressure and axial compression in order to deform an objective shape. THF has less restriction on shape and size of workpieces owing to adopting the liquid tool. The demand of a small diameter magnesium alloy tubular parts have been increased for applying small medical and electronic devices. In this study, it was investigated that influence of process conditions such as processing temperature, internal pressure and axial feeding amount on formability of small diameter ZM21 magnesium alloy tube with outer diameter of 2.0mm and thickness of 0.20mm. Furthermore, the processing conditions for improving the formability of material in THF were examined. For prior evaluation of deformation characteristics in the warm THF of small diameter ZM21 magnesium alloy tube, a finite element (FE) simulation was conducted. The FE method (FEM) code was used LS-DYNA 3D for analysis of the FE model of the tube and the dies. The material characteristics were obtained by tensile test and fracture test. From FE analysis results, it was elucidated that effect of the processing temperature, the variable internal pressure and the axial feeding amount on deformation behavior. The formability of ZM21 magnesium alloy tube was improved by processing at 250 C. The difference of deformation characteristic between FE results and experimental results was compared. As the results, the processing condition which could improve the formability of ZM21 tube was clarified using this FE model. The effect of adding the straightening stage in the loading path after the preform on formability was investigated. The thinning of the wall thickness of the tube was inhibited by calibration after the axial feeding
Electromagnetic K+ production on the deuteron with hyperon recoil polarization
Photo- and electroproduction processes of K+ on the deuteron are investigated
theoretically. Modern hyperon-nucleon forces as well as an updated kaon
production operator on the nucleon are used. Sizable effects of the
hyperon-nucleon final state interaction are seen in various observables.
Especially the photoproduction double polarization observable C_z is shown to
provide a handle to distinguish different hyperon-nucleon force models.Comment: 4 pages, 7 eps-figures, talk given at the VII International
Conference on Hypernuclear and Strange Particle Physics, Torino, Italy,
October 23-27, 2000, to appear in the proceedings (Nucl. Phys. A
NMR Evidence for Antiferromagnetic Transition in the Single-Component Molecular Conductor, [Au(tmdt)_{2}] at 110 K
We present the results of a ^{1}H NMR study of the single-component molecular
conductor, [Au(tmdt)_{2}].
A steep increase in the NMR line width and a peak formation of the nuclear
spin-lattice relaxation rate, 1/T_{1}, were observed at around 110 K.
This behavior provides clear and microscopic evidences for a magnetic phase
transition at considerably high temperature among organic conductors.
The observed variation in 1/T_{1} with respect to temperature indicates the
highly correlated nature of the metallic phase.Comment: 5pages, 6figures to be published in J. Phys. Soc. Jp
Direct evidence for ferromagnetic spin polarization in gold nanoparticles
We report the first direct observation of ferromagnetic spin polarization of
Au nanoparticles with a mean diameter of 1.9 nm using X-ray magnetic circular
dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold
magnetization is explored. Magnetization of gold atoms estimated by XMCD shows
a good agreement with the results obtained by conventional magnetometry. This
result is evidence of intrinsic spin polarization in nano-sized gold.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let
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