High momentum components of the deuteron wave function

The tail of spectator distribution for the reaction K⁺d ?K⁺ π^?pp is studied with the inclusion of inelastic intermediate states in the double scattering. The result seems to indicate the existence of high momentum components for the deuteron wave function.     

Kinetically limited growth of GaAsBi by molecular-beam epitaxy

The growth of GaAsBi alloys is plagued by the appearance of Bi droplets due to excess Bi that accumulates during growth. Here we present an alternate growth regime that kinetically limits the amount of Bi on the surface, eliminating Bi droplets for a wide range of Bi compositions, while yielding atomically smooth surfaces. Growth rate plays a major role in the amount of Bi that accumulates on the surface, with high growth rates and low Bi fluxes leading to less surface Bi. A balance can be achieved between low Bi coverage, the resultant rough surfaces, and the excessive Bi coverage that leads to Bi droplets. Bi incorporation in this growth regime is linear with Bi flux and scales inversely with growth rate. Unlike previous studies, there is no sign of saturating Bi incorporation with increasing Bi flux, allowing for intuitive prediction and control of Bi content in this regime.     

Diffusion in a closed basin and boundary reflection

Summary In this paper the diffusion equation is solved with the eigenvalue method for a rectangular and a circular basin. Peculiar phenomena of accumulation of pollutant are observed in the corresponding numerical investigation. These phenomena are interpreted in terms of multiple reflection on the boundary, in a suitable generalization of the image source method in the two-dimensional case.

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Riassunto In questo lavoro l'equazione di diffusione è risolta per un bacino rettangolare ed uno circolare con il metodo degli autovalori. Particolari fenomeni di accumulazione si sono osservati nel corrispondente studio numerico. Questi fenomeni sono interpretati in termini di diffusione multipla sul contorno in un'opportuna generalizzazione del metodo della sorgente immagine al caso bidimensionale.

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Резюме В зтой статье решается уравнение диффузии с помощью метода собственных знаачений для прямоугольного и круглого бассейнов. При соответствующем численном исследовании наблюдаются специфические явления накапливания загряз-няющих веществ. Эти явления интерпретируются в терминах многократного отражения от границ, при соответствующем обобщении метода мнимых источников в двумерном случае.

     

Inadequacy of the spectator model in deuteron break-up induced by high-energy hadrons

We discuss the experimental features of the spectator distribution in high-energy reactions on deuterons and we compare them with the quantitative and qualitative predictions of various theoretical models. We find that only a particular type of meson exchange can explain the relative channel dependence. Extending our analysis to the case of a hyperon and a nucleon in the final state, we find it more practical to look at this effect from a different point of view, namely introducing isobars in the final scattering state.     

On the parametrization of pion nucleon scattering amplitude at energies less than 2 GeV

It is shown that 0⁺ pairing vibrations are associated with rather large mean square values of the quadrupole moment, indicating a pronounced intrinsic deformation. This deformation is demonstrated using a two level model, where the pairing vibration can be treated analytically within the quasi boson approximation. The results are compared with the data for the 6.06 MeV state in O¹⁶.     

Recoil effect in quasi-elastic hadron-deuteron scattering

The problem of hadron-deuteron quasi-elastic scattering is considered for large momentum transfers. The longitudinal part of the momentum transfer is included in the single and double scattering. It is shown that a simple enhancement factor relates the double scattering contribution to the differential cross section to the same quantity in Glauber theory.     

The Landé g-factor in atomic spectroscopy

The role of the Landé g-factor in atomic spectroscopy is explored through theoretical studies for Ne I and Ne II where some experimental values are available. Extended correlation studies in the Breit–Pauli approximation for spectrum calculations are analysed and compared with experiment and other theory. For Ne II, the multiconfiguration Dirac–Hartree–Fock method was also applied, but correlation was restricted only to the effect of core-polarization on the outer electron.     

Differential cross sections for K+n elastic scattering between 0.64 and 1.51 GeV/c

We present experimental results on the K⁺n → K⁺n differential cross sections measured in deuterium at 13 momenta between 0.64 and 1.51 GeV/c.     

Metal-insulator transition by isovalent anion substitution in Ga1-xMnxAs: implications to ferromagnetism

We have investigated the effect of partial isovalent anion substitution in Ga1-xMnxAs on electrical transport and ferromagnetism. Substitution of only 2.4% of As by P induces a metal-insulator transition at a constant Mn doping of x=0.046 while the replacement of 0.4% As with N results in the crossover from metal to insulator for x=0.037. This remarkable behavior is consistent with a scenario in which holes located within an impurity band are scattered by alloy disorder in the anion sublattice. The shorter mean free path of holes, which mediate ferromagnetism, reduces the Curie temperature T_{C} from 113 to 60 K (100 to 65 K) upon the introduction of 3.1% P (1% N) into the As sublattice.