451 research outputs found

    On Combining High and Low Q**2 Information on the Polarized Parton Densities

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    We draw attention to some problems in the combined use of high-Q^2 deep inelastic scattering (DIS) data and low-Q^2 hyperon \beta-decay data in the determination of the polarized parton densities. We explain why factorization schemes like the JET or AB schemes are the simplest in which to study the implications of the DIS parton densities for the physics of the low-Q^2 region.Comment: 10 pages, LaTeX, minor corrections made in Section 4, a reference added, to be published in JHE

    Constraints on "Second Order Fixed Point" QCD from the CCFR Data on Deep Inelastic Neutrino-Nucleon Scattering

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    The results of LO {\it Fixed point} QCD (FP-QCD) analysis of the CCFR data for the nucleon structure function  xF3(x,Q2) ~xF_3(x,Q^2)~ are presented. The predictions of FP-QCD, in which the Callan-Symanzik  β ~\beta~ function admits a {\it second order} ultraviolet zero at  α=α0 ~\alpha = \alpha_0~ are in good agreement with the data. Constraints for the possible values of the  β ~\beta~ function parameter  b ~b~ regulating how fast  αs(Q2) ~\alpha_ s(Q^2)~ tends to its asymptotic value  α0≠0 ~\alpha_{0}\ne 0~ are found from the data. The corresponding values of  α0 ~\alpha_{0}~ are also determined. Having in mind our recent " First order fixed point" QCD fit to the same data we conclude that in spite of the high precision and the large  (x,Q2) ~(x,Q^2)~ kinematic range of the CCFR data they cannot discriminate between QCD and FP-QCD predictions for  xF3(x,Q2) ~xF_3(x,Q^2)~.Comment: 8 pages, LaTe

    EAS fluctuation approach to primary mass composition investigation

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    The analysis of muon and electron fluctuation distribution shapes by statistical method of invers problem solution gives the possibility to obtain the relative contribution values of the five main primary nuclei groups. The method is model-independent for a big class of interaction models and can give good results for observation levels not too far from the development maximum and for the selection of showers with fixed sizes and zenith angles not bigger than 30 deg
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