Global QCD fit from Q{sup 2}=0 to Q{sup 2}=30 000 GeV{sup 2} with Regge-compatible initial condition

Journal Article · Fri Apr 01 04:00:00 EST 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.71.076001· OSTI ID:20709015

Soyez, G ^[1]

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1. SPhT, CEA Saclay, ORme des Merisiers, Bat 774, F-91191 Gif-sur-Yvette cedex (France)

In this paper I show that it is possible to use Regge theory to constrain the initial parton distribution functions of a global Dokshitzer, Gribov, Lipatov, Altarelli, and Parisi (DGLAP) fit. In this approach, both quarks and gluons have the same high-energy behavior which may also be used to describe soft interactions. More precisely, I show that, if we parametrize the parton distributions with a triple-pole pomeron, i.e. like log{sup 2}(1/x) at small x, at Q{sup 2}=Q{sub 0}{sup 2} and evolve these distributions with the DGLAP equation, we can reproduce F{sub 2}{sup p}, F{sub 2}{sup d}, F{sub 2}{sup n}/F{sub 2}{sup p}, F{sub 2}{sup {nu}}{sup N}, and xF{sub 3}{sup {nu}}{sup N} for W{sup 2}{>=}12.5 GeV{sup 2}. In this case, we obtain a new leading-order global QCD fit with a Regge-compatible initial condition. I shall also show that it is possible to use Regge theory to extend the parton distribution functions to small Q{sup 2}. This leads to a description of the structure functions over the whole Q{sup 2} range based on Regge theory at low Q{sup 2} and on QCD at large Q{sup 2}. Finally, I shall argue that, at large Q{sup 2}, the parton distribution functions obtained from DGLAP evolution and containing an essential singularity at j=1 can be approximated by a triple-pole pomeron behavior.

• OSTI ID: 20709015
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 71; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DISTRIBUTION
DISTRIBUTION FUNCTIONS
GLUONS
PARTICLE INTERACTIONS
PARTONS
QUANTUM CHROMODYNAMICS
QUARKS
REGGE CALCULUS
SINGULARITY
STRUCTURE FUNCTIONS