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arXiv · hep-ph/9703420

Unpolarized and polarized quark distributions in the large-Nc limit

D. I. Diakonov·V. Yu. Petrov·P. V. Pobylitsa·M. V. Polyakov·C. Weiss
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Abstract

The isosinglet unpolarized and isovector polarized twist-2 quark distributions of the nucleon at low normalization point are calculated in the large-Nc limit. The nucleon is described as a soliton of the effective chiral theory. We derive the expressions for the distribution functions in the large-Nc limit starting from their definition as numbers of partons carrying momentum fraction x in the infinite momentum frame. We develop a numerical method for computation of the quark and antiquark distributions as sums over the quark single-particle levels in the pion field of the soliton. The contributions of the discrete bound-state level as well as the Dirac continuum are taken into account. The quark- and antiquark distributions obtained explicitly satisfy all general requirements. Results are in reasonable agreement with parametrizations of the data at low normalization point.

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D. I. Diakonov, V. Yu. Petrov, P. V. Pobylitsa, M. V. Polyakov, C. Weiss. 1997-03-25. Unpolarized and polarized quark distributions in the large-Nc limit. https://doi.org/10.1103/physrevd.56.4069

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