Eur. Phys. J. C (2008) 56: 221-229
https://doi.org/10.1140/epjc/s10052-008-0651-1

Regular Article - Theoretical Physics

Quark sea structure functions of the nucleon in a statistical model

¹ Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84010-790, Ponta Grossa, PR, Brazil
² Instituto de Física Teórica, Universidade Estadual Paulista, Rua Pamplona, 145, 01405-900, São Paulo, SP, Brazil
³ Departamento de Física, Instituto Tecnológico de Aeronáutica, CTA, 12228-900, São José dos Campos, SP, Brazil

^* e-mail: tomio@ift.unesp.br

Received: 12 May 2008
Revised: 21 May 2008
Published online: 2 July 2008

Abstract

Within a statistical model of linear confined quarks we obtain the flavor asymmetry and corresponding structure function of the nucleon. The model parameters are fixed by the experimental available data. The temperature parameter is adjusted by the Gottfried sum rule violation and the chemical potentials by the corresponding up (u) and down (d) quark normalizations in the nucleon. The light antiquark and quark distributions in the proton, given by d̄/ū, d/u and d̄-ū, as well as the neutron to proton ratio of the structure functions, extracted from the experimental data, are well fitted by the model. As the quark-confining strengths should be flavor dependent, a mechanism is introduced in the model to adjust the corresponding distribution, in order to improve the comparison obtained for the sea-quark asymmetries in the nucleon with the available experimental analysis.