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Universality and scaling in perturbative QCD at small x
We present a pedagogical review of the universal scaling properties displayed by the structure function F_2 at small x and large Q^2 as measured at HERA. We first describe the derivation of the double asymptotic scaling of F_2 from the leading-order Altarelli-Parisi equations of perturbative QCD. Un...
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Lenguaje: | eng |
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1995
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Acceso en línea: | http://cds.cern.ch/record/292347 |
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author | Forte, Stefano Ball, Richard D. |
author_facet | Forte, Stefano Ball, Richard D. |
author_sort | Forte, Stefano |
collection | CERN |
description | We present a pedagogical review of the universal scaling properties displayed by the structure function F_2 at small x and large Q^2 as measured at HERA. We first describe the derivation of the double asymptotic scaling of F_2 from the leading-order Altarelli-Parisi equations of perturbative QCD. Universal next-to-leading order corrections to scaling are also derived. We explain why the universal scaling behaviour is spoiled when the initial distributions rise too steeply by considering the nonsinglet distribution F_2^p-F_2^n as an explicit example. We then examine the stability of double scaling to the inclusion of higher order singularities, explaining how the perturbative expansion at small x can be reorganized in such a way that each order is given by the sum of a convergent series of contributions which are of arbitrarily high order in the coupling. The wave-like nature of perturbative evolution is then shown to persist throughout almost all the small x region, giving rise asymptotically to double scaling for a wide class of boundary conditions. |
id | cern-292347 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 1995 |
record_format | invenio |
spelling | cern-2923472022-08-13T02:25:04Zhttp://cds.cern.ch/record/292347engForte, StefanoBall, Richard D.Universality and scaling in perturbative QCD at small xParticle Physics - PhenomenologyWe present a pedagogical review of the universal scaling properties displayed by the structure function F_2 at small x and large Q^2 as measured at HERA. We first describe the derivation of the double asymptotic scaling of F_2 from the leading-order Altarelli-Parisi equations of perturbative QCD. Universal next-to-leading order corrections to scaling are also derived. We explain why the universal scaling behaviour is spoiled when the initial distributions rise too steeply by considering the nonsinglet distribution F_2^p-F_2^n as an explicit example. We then examine the stability of double scaling to the inclusion of higher order singularities, explaining how the perturbative expansion at small x can be reorganized in such a way that each order is given by the sum of a convergent series of contributions which are of arbitrarily high order in the coupling. The wave-like nature of perturbative evolution is then shown to persist throughout almost all the small x region, giving rise asymptotically to double scaling for a wide class of boundary conditions.We present a pedagogical review of the universal scaling properties displayed by the structure function F_2 at small x and large Q^2 as measured at HERA. We first describe the derivation of the double asymptotic scaling of F_2 from the leading-order Altarelli-Parisi equations of perturbative QCD. Universal next-to-leading order corrections to scaling are also derived. We explain why the universal scaling behaviour is spoiled when the initial distributions rise too steeply by considering the nonsinglet distribution F_2^p-F_2^n as an explicit example. We then examine the stability of double scaling to the inclusion of higher order singularities, explaining how the perturbative expansion at small x can be reorganized in such a way that each order is given by the sum of a convergent series of contributions which are of arbitrarily high order in the coupling. The wave-like nature of perturbative evolution is then shown to persist throughout almost all the small x region, giving rise asymptotically to double scaling for a wide class of boundary conditions.hep-ph/9512208CERN-TH-95-323EDINBURGH-95-560CERN-TH-95-323EDINBURGH-95-560oai:cds.cern.ch:2923471995-12-01 |
spellingShingle | Particle Physics - Phenomenology Forte, Stefano Ball, Richard D. Universality and scaling in perturbative QCD at small x |
title | Universality and scaling in perturbative QCD at small x |
title_full | Universality and scaling in perturbative QCD at small x |
title_fullStr | Universality and scaling in perturbative QCD at small x |
title_full_unstemmed | Universality and scaling in perturbative QCD at small x |
title_short | Universality and scaling in perturbative QCD at small x |
title_sort | universality and scaling in perturbative qcd at small x |
topic | Particle Physics - Phenomenology |
url | http://cds.cern.ch/record/292347 |
work_keys_str_mv | AT fortestefano universalityandscalinginperturbativeqcdatsmallx AT ballrichardd universalityandscalinginperturbativeqcdatsmallx |