Global QCD fit from Q{sup 2}=0 to Q{sup 2}=30 000 GeV{sup 2} with Regge-compatible initial condition
- 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, Vol. 71, Issue 7; Other Information: DOI: 10.1103/PhysRevD.71.076001; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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