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Longitudinal polarization of $\ensuremath{\Lambda}$ produced in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at CERN LEP energies is calculated in a picture for the spin content of $\ensuremath{\Lambda}$ which is consistent with the polarized deep inelastic lepton-nucleon scattering data and SU(3) flavor symmetry for hyperon decay, so that the spin of $\ensuremath{\Lambda}$ is not completely carried by its $s$-valence quark. A comparison with the recent ALEPH data and the results of earlier calculations based on the static quark model, in which the spin of $\ensuremath{\Lambda}$ is completely determined by the $s$ quark, is given. The result shows that further measurements of such polarization should provide useful information as to the question of which picture is more suitable in describing spin effects in the fragmentation processes.

It is shown that the polarization of hyperons observed in high energy collisions using unpolarized hadron beams and unpolarized nucleon or nuclear targets is closely related to the left-right asymmetries observed in single spin inclusive hadron production processes. The relationship is most obvious for the production of the hyperons which have only one common valence quark with the projectile. Examples of this kind are given. Further implications of the existence of large polarization for hyperon which has two valence quarks in common with the projectile and their consequences are discussed. A comparison with the available data is made. Further tests are suggested., Comment: REVTeX, 12 pages, 2 figures embedded

We show that quark-antiquark annihilation processes in single-spin inclusive production experiments can yield useful information on hadron spin structure in general, and provide crucial tests for the existence of orbiting valence quarks in particular. There are several experimental indications and theoretical arguments for the existence of such orbital motion inside polarized protons or antiprotons. Simple relations between quark-spin distributions and left-right asymmetries in such production processes can be given, and quantitative predictions can be made.

In situ synchrotron and neutron diffraction were used to study deformation mechanisms in Ni over a broad range of grain sizes. The experimental data show that unlike in coarse-grained metals, where the deformation is dominated by dislocation slip, plastic deformation in nanocrystalline Ni is mediated by grain-boundary activities, as evidenced by the lack of intergranular strain and texture development. For ultrafine-grained Ni, although dislocation slip is an active deformation mechanism, deformation twinning also plays an important role, whose propensity increases with the grain size.

Under the assumption that in {ital e}{sup +}{ital e}{sup {minus}} annihilations baryons and antibaryons are produced by the stochastic combination of quarks and antiquarks, the baryon-antibaryon flavor correlations come completely from the global compensation of the flavors of all of the quarks and antiquarks. This can at least provide us with a lower limit for the baryon-antibaryon flavor correlations in various models, and by comparing them with experiment, we can see if and to what extent one has the necessity or freedom to introduce any other mechanism to produce extra baryon-antibaryon flavor correlations. Starting from this assumption, we have made calculations on {l angle}{ital n}{sub {Lambda}{bar {Lambda}}}{r angle}/{l angle}{ital n}{sub {Lambda}}{r angle}, {l angle}{ital n}{sub {Xi}{sup {minus}}{bar {Lambda}}}{r angle}/{l angle}{ital n}{sub {Xi}{sup {minus}}}{r angle}, and {l angle}{ital n}{sub {Lambda}(1520){bar {Lambda}}}{r angle}/{l angle}{ital n}{sub {Lambda}(1520)}{r angle}, which have already been measured, and on similar quantities such as {l angle}{ital n}{sub {Sigma}{sup {plus minus}}{bar {Lambda}}}{r angle}{l angle}{ital n}{sub {Sigma}{sup {plus minus}}}{r angle}, {l angle}{ital n}{sub {Sigma}{sup *{plus minus}}{bar {Lambda}}}{r angle}/{l angle}{ital n}{sub {Sigma}{sup *{plus minus}}}{r angle},{l angle}{ital n}{sub {Xi}{sup *{minus}}{bar {Lambda}}}{r angle}{l angle}{ital n}{sub {Xi}{sup *{minus}}}{r angle}, and {l angle}{ital n}{sub {Omega}{sup {minus}}{bar {Lambda}}}{r angle}/{l angle}{ital n}{sub {Omega}{sup {minus}}}{r angle}, which havemore » not been measured yet. Comparing with the available data, it seems that there is little room left for other mechanisms which result in extra flavor correlations.« less

It is suggested that the nonzero analyzing power {ital A} observed in large-{ital p}{sub {perpendicular}}{sup 2} elastic {ital pp}({up arrow}) scattering is an indication for the existence of rotating color charges in polarized protons. Such color charges induce color-magnetic fields and thus give rise to an additional, velocity-dependent, interaction. The effects of this interaction are discussed phenomenologically at the hadronic level.

The in situ time-of-flight neutron-diffraction measurements captured well the martensitic transformation behavior of the Ni-Mn-Ga ferromagnetic shape-memory alloys under uniaxial stress fields. We found that a small uniaxial stress applied during phase transformation dramatically disturbed the distribution of variants in the product phase. The observed changes in the distributions of variants may be explained by considering the role of the minimum distortion energy of the Bain transformation in the effective partition among the variants belonging to the same orientation of parent phase. It was also found that transformation kinetics under various stress fields follows the scale law. The present investigations provide the fundamental approach for scaling the evolution of microstructures in martensitic transitions, which is of general interest to the condensed matter community.

We study the polarization of antihyperon in lepton induced reactions such as $e^+e^-\to\bar H+X$ and $l+p\to l'+\bar H+X$ with polarized beams using different models for spin transfer in high energy fragmentation processes. We compare the results with the available data and those for hyperons. We make predictions for future experiments., 31 pages, 6 figures. submitted to Phys. Rev. D. content changed, references added

We apply the picture proposed in a previous Letter, which relates the hyperon polarization in unpolarized hadron-hadron collisions to the left-right asymmetry in singly polarized reactions, to the production of different hyperons in reactions using different projectiles and/or targets. We discuss the different ingredients of the proposed picture in detail and present the results for hyperon polarization in the reactions such as $pp$, $K^-p$, $\pi^{\pm}p$, and $\Sigma^-p$ collisions. We compare the results with the available data and make predictions for future experiments., Comment: 41pages, 7 figures, content changed

Using the same method as that used in $e^+e^-$ annihilation and lepton-nucleon deep-inelastic scattering, we calculate the spin alignment of vector mesons with high transverse momenta in high energy $pp$ collisions with one longitudinally polarized beam. We present the results obtained at RHIC energies. We also study the spin alignment of such vector mesons in the case of a transversely polarized proton beam and present its relation to the transversity distribution in the nucleon. Numerical results obtained using simple models for the transversity distributions are also given. These results show that there exist significant spin alignment in both cases, and they can be measured in experiments such as those at RHIC.

We extend the calculations of the spin alignments of vector mesons in $e^+e^-$ annihilation in a recent Rapid Communication to deeply inelastic lepton-nucleon scatterings. We present the results for different mesons in the current fragmentation regions of $\mu^- N$$ \to$$ \mu^- VX$ at high energies and $\nu_\mu N $$\to$$ \mu^- VX$ at both high and low energies. We also present the predictions for $\nu_\mu N$$ \to$$ \mu^- VX$ at NOMAD energies in the target fragmentation region using a valence quark model., Comment: 4 pages, 6 figures; to appear in Phys. Rev. D

We apply the picture proposed in a recent Letter for transverse hyperon polarization in unpolarized hadron-hadron collisions to the exclusive process ${e}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{-}}\mathrm{HK}$ such as ${e}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{-}}\ensuremath{\Lambda}{K}^{+},$ ${e}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{-}}{\ensuremath{\Sigma}}^{+}{K}^{0},$ or ${e}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{-}}{\ensuremath{\Sigma}}^{0}{K}^{+},$ or the similar process ${e}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{-}}n{\ensuremath{\pi}}^{+}$ with longitudinally polarized electron beams. We present the predictions for the longitudinal polarizations of the hyperons or neutron in these reactions, which can be used as further tests of the picture.

Longitudinal polarizations of different kinds of hyperons produced in e+e- annihilation at LEP I and LEP II energies in different event samples are calculated using two different pictures for the spin structure of hyperon: that drawn from polarized deep inelastic lepton-nucleon scattering data or that using SU(6) symmetric wave functions. The result shows that measurements of such polarizations should provide useful information to the question of which picture is more suitable in describing the spin effects in the fragmentation processes.