Transversity distribution and polarized fragmentation function from semi-inclusive pion electroproduction

A method is discussed to determine the hitherto unknown u-quark transversity distribution from a planned HERMES measurement of a single target-spin asymmetry in semi-inclusive pion electroproduction off a transversely polarized target. Assuming u-quark dominance, the measurement yields the shapes of the transversity distribution and of the ratio , of polarized and unpolarized u-quark fragmentation functions. The unknown relative normalization can be obtained by identifying the transversity distribution with the well-known helicity distribution at large x and small . The systematic uncertainty of the method is dominated by the assumption of u-quark dominance. Received: 18 June 2000 / Revised version: 20 November 2000 / Published online: 5 February 2001     

Neutral strange particle production in charged current νA-interactions in the energy range 3≦E ν≦30 GeV

For charged current neutrino nucleus interactions at energies below 30 GeV, resulting from an experiment with the freon filled bubble chamber SKAT,K ⁰ and Λ production is investigated. An estimation of the total strange and charm production cross section is made.K ⁰ and Λ production rates are given in dependence on different inclusive variables. The production properties forK ⁰′s and Λ′s are discussed in terms of the Quark-Parton-Model. Comparisons with other ν-experiments at higher energies are performed.     

Observation ofD S ** (2536) meson production by neutrinos in BEBC

Zeitschrift für Physik C Particles and Fields - Neutrino interactions in BEBC produce theD ** (2536) charmed strange meson. The mass of this state is 2534.2±1.2 MeV. The production rate...     

Simultaneous determination of dyes of different classes in aquaculture products and spices using HPLC–high-resolution quadrupole time-of-flight mass spectrometry

A simple method of sample preparation, rapid screening, and determination of dyes—veterinary drugs and illegally used dyes (coloring product counterfeiters)—in spices by HPLC–high-resolution quadrupole time-of-flight mass spectrometry is proposed. Sample preparation involves the extraction of analytes from a solid matrix with acetonitrile containing 0.1% of formic acid, twofold dilution of the extract with deionized water, filtration, and chromatographic separation. The limits of detection were 0.01–0.4 ng/g. The procedure of screening and determination of dyes in foods includes the identification of dyes by an accurate monoisotopic mass of the ion (m/z), retention time (t _R), and coincidence of the isotopic distribution (mSigma), and, if dyes are detected, their determination by the standard addition method. The relative standard deviation of the results does not exceed 15%. The duration of the analysis is 1–2 h.     

ZrO<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> binary oxides as promising supports for palladium catalysts of hydrodechlorination

Deposited palladium catalysts of the hydrodechlorination of 1,3,5-trichlorobenzene were studied. Pure zirconium and aluminum oxides and ZrO₂-Al₂O₃ mixtures with 1, 5, and 10 mol % Al₂O₃ prepared by coprecipitation were used as supports. Palladium was deposited by the precipitation of its hydroxide on supports. Catalysts on binary supports (ZrO₂ + 1% Al₂O₃ and ZrO₂ + 5% Al₂O₃) exhibited higher activity and stability in hydrodechlorination compared with catalysts on pure supports. The suggestion was made that the high activity and stability of these systems in hydrodechlorination was related to the formation of binary oxide in the interaction of ZrO₂ with palladium oxide at the stage of annealing of the catalyst precursor. Binary oxide, which was a center of the activation of the C-Cl bond, was simultaneously a source of active hydrogen. The presence of various palladium states in catalysts was substantiated by the temperature programmed reduction method.     

About the Limit Spectra of Some Unbounded Selfadjoint Integral Operators

Siberian Mathematical Journal - We establish sufficient conditions for the zero to belong to the limit spectra of some unbounded selfadjoint integral operator.     

Reduction of operator families to integral form

We establish a condition for reducibility of a family of operators to integral form by an isometric operator the same for the whole family.     

Automatic Baseline Construction Using Vertical Histograms

An algorithm is proposed for automatic baseline construction in the absence of a priori information about the shape of the experimental curve and the arrangement of basic portions in the experimental curve. The functioning of the algorithm is considered for the case when the basic portion of the curve is distorted with a parasitic signal of an intricate shape.__________Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 7, 2005, pp. 692–697.Original Russian Text Copyright © 2005 by Korotkov.