New 5 flavor next-to-leading-order analysis and parametrizations of parton distributions of the real photon

Journal Article · Mon Nov 01 04:00:00 EST 2004 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.70.093004· OSTI ID:20705583

Cornet, F; Jankowski, P; Krawczyk, M ^[1]

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1. Departamento de Fisica Teorica y del Cosmos, Universidad de Granada, Campus de Fuente Nueva, E-18071, Granada (Spain)

New, radiatively generated, next-to-leading (NLO) quark (u,d,s,c,b) and gluon densities in a real, unpolarized photon are presented. We perform three global fits, based on the NLO Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations for Q{sup 2}>1 GeV{sup 2}, to all the available structure-function F{sub 2}{sup {gamma}}(x,Q{sup 2}) data. As in our previous LO analysis we utilize two theoretical approaches. Two models, denoted as FFNS{sub CJK}1 and FFNS{sub CJK}2 NLO, adopt the so-called fixed flavor-number scheme for calculation of the heavy-quark contributions to F{sub 2}{sup {gamma}}(x,Q{sup 2}); the Cornet-Jankowski-Krawczyk NLO model applies the ACOT({chi}) scheme. We examine the results of our fits by a comparison with the LEP data for the Q{sup 2} dependence of the F{sub 2}{sup {gamma}}, averaged over various x regions, and the F{sub 2,c}{sup {gamma}}. Grid parametrizations of the parton densities for all fits are provided.

• OSTI ID: 20705583
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 9 Vol. 70; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
B QUARKS
C QUARKS
COMPARATIVE EVALUATIONS
DISTRIBUTION
FLAVOR MODEL
GLUONS
LEP STORAGE RINGS
PARTON MODEL
PARTONS
PHOTONS
QUANTUM CHROMODYNAMICS
STRUCTURE FUNCTIONS
T QUARKS