Transversely polarized parton densities,their evolution and their measurement

The transverse spin asymmetry of a quark in a baryon and the linear polarization of a gluon in a vector meson are studied from thet-channel point of view. Using the Altarelli-Parisi approach, they are shown to obey independent evolution equations and to decrease with increasingQ ². We investigate the possibility to measure them at leading twist, to leading order in α and α_s and without analyzing the final polarizations. This requires simultaneous polarization of the beam and the target; the observable effect is in the azimuthal distribution of the highP _T particle or jet. Assuming a simple (quark+scalar diquark) model for the baryon, a large asymmetry is expected inp \(\bar p\) Drell-Yan collisions, a smaller one in highP _T pp collisions, from the interference term in the scattering of two identical quarks.     

High dose iron implantation into silicon and metals

High dose implantations of Fe into metals and semiconductors have been performed with beam energies up to 1 MeV at the UNILAC-injector at GSI. Unusual high concentrations of 70 atomic % for Si and 20 atomic % for Cu have been obtained, with doses of 10¹⁸ Fe/cm² in the case of Si and several 10¹⁷ Fe/cm² in the case of Cu. For Si the thickness of the layers were determined by Rutherford backscattering to be 4500 Å. These results are consistent with calculations, which show that these high concentrations are due to the reduction of the sputter yield at the relative high particle energies. Samples have been characterized using several complementary methods (Mössbauer Spectroscopy (MS), Rutherford Backscattering Spectroscopy (RBS), Auger electron Spectroscopy (AES). Scanning Electron Microscopy (SEM), X-ray diffraction (XRD)).     

Synthesis and crystal and molecular structure of newN-substituted γ-hydroxybutyramides

TheN-(2-phenylethyl)amide of-(1, 1-ethylenedioxy)-ethyl--hydroxybutyric acid (II) and theN-(p-methoxybenzyl)amide of-(1, 1-ethylenedioxy)-ethyl--hydroxybutyric acid (III) have been synthesized and the crystal structure ofIII has been solved. CompoundIII, C₁₆H₂₃O₅N, crystallizes in the monoclinic space groupP2₁/c witha=12.572(2),b=11.149(2),c=12.317(2) Å and=106.53(1)°. The structure was solved by direct methods, and refined by full-matrix least squares to giveR=0.040 (R _w =0.047) for 2004 intensities. The dioxolane ring has a deformed half-chair conformation.     

Crystal structure and vibrational spectra of hydrazinium (2+) tri-μ-fluoro bis[pentafluorozirconate (IV)] fluoride and vibrational spectra of its hafnium analogue

Monoclinic (N₂H₆)₃Zr₂F₁₃·F crystallizes in space group P2₁-C ₂ ² (No. 4) with unit cell dimensionsa=5.670(1),b=10.984(2),c=10.601(2) Å,=93.88(1)°,V=658.7(4) ų andZ=2. Two different types of N₂H₆ ²⁺ ions are present. One is involved in strong H-bonds to F^– ions in infinite chains running along the a axis (the shortest N-F distance is 2.437(5) Å), and the other links the structure through weaker bi- and trifurcated H-bonds to fluorine ligands of the Zr₂F₁₃ ^5– ions. The N-N bond lengths range from 1.430(5) to 1.446(5) Å with apparently no meaningful correlation to the type of N₂H₂ ²⁺ ions. The Zr₂F₁₃ ^5– ions have very nearly C₂ point symmetry and are formed by joining two distorted bicapped trigonal prisms of ZrF₈-units through a common face. Distances of Zr-F terminal bonds range from 2.015(2) to 2.112(2) Å and of bridging bonds from 2.133(2) to 2.212(2) Å. (N₂H₆)₃Hf₂F₁₃·F is isomorphous. The vibrational spectra of the two compounds are nearly identical, with the exception of a strong infrared band, which is assigned to a stretching mode with the moving central atom within the anion. The anion part of the spectrum is simple, showing broad unresolved bands. The cation part shows two types of N₂H₆ ^– ions. H-Bonding is strongly present in the spectra, but no simple correlations with the H-bond strength is evident.     

Crystal and molecular structure of crenatine carbonate

The crystal and molecular structure of 1-ethyl-4-methoxy-9H-pyrido[3,4b]indole (crenatine) carbonate C₁₄H₁₄N₂O·H₂CO₃, (MS, m/z 226)M _R 288.3, a-carboline alkaloid, has been determined from X-ray diffraction data. The compound crystallizes in the space group Pbca with cell parameters:a=11.616(4),b=18.450(8),c=12.992(5)Å,V=2784(2)ų,Z=8,D _calc=1.375 g cm^–3, (MoK)=0.71069Å,(Mo K)=0.94 cm^–1,F(000)=1216,R/R _w =8.2/10.3% for 1099 reflections. The ring system of the-carboline nucleus is planar. The title compound shows a two center hydrogen bond between the indole N-H group and the oxygen atom of a carbonate group. The structure does not display hydrogen bonding between-carboline groups but rather a bonding network involving the carbonate group.     

Impulse systems with fixed moments of shocks of general position: The structure of the set of moments of the shocks

Ordinary differential equations with impulse action are considered at fixed moments of time when finite limits points are admitted to the set of moments of the shocks. The topological structure of this set is clarified: it must be resolvable, in particular nowhere dense in R.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 42, No. 3, pp. 378–383, March, 1990.     

Electron Emission from Clean Solid Surfaces by Fast Ions

Total backward electron yields from 27 elemental, non-crystalline, clean solids were measured during bombardment by H⁺-, H-, H-, He⁺- and Ar⁺-ions in the energy range from 100 keV to 800 keV. The yields were found to exhibit an oscillatory dependence on the atomic number of the target material correlated with the periods of the periodic system. These Z₂-oscillations are relatively insensitive to the type of projectile and the impact energy at the high projectile energies of this experiment. Present theories of electron emission cannot explain the main experimental results. The reasons for this failure are discussed.     

Behavior of effective charges in e6 grand unification theory in curved spacetime

The behavior of effective charges _i(t) corresponding to the parameters of nonminimal coupling of scalar and gravitational fields in E₆ Grand Unification Theory (GUT) in curve spacetimes is studied. It is shown that in a strong gravitational field ¦_i(t)¦ grows indefinitely.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 74–11, September, 1990.     

Disordered charge distributions and dielectric loss in extra dense flint glasses

The complex permittivities of some extra dense flint glasses (EDF glasses) have been studied. The dielectric features of the samples are dominated by their PbO content. Both refractive indices and dielectric losses exhibit a close relation to the concentration of Pb ions. The latter are located either at sites of the network atoms or filling the potential minima interstitially. They can be identified by their different relaxation mechanisms. The dispersion in the submillimeter wave and FIR area is characterized by a very broad distribution of comparably sharp resonant states. Thermal lens — or hysteresis effects can be excluded.