https://doi.org/10.1140/epjc/s2003-01528-2
theoretical physics
gluon distribution and structure functionsin the loop-loop correlation model
1
Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 19, 69120, Heidelberg, Germany
2
Institut de Physique, Bâtiment B5, Université de Liége, Sart-Tilman, 4000, Liége, Belgium
* e-mail: pir@tphys.uni-heidelberg.de
We consider the interaction of the partonic fluctuation of a scalar “photon” with an external color field to calculate the leading and next-to-leading order gluon distribution of the proton following the work done by Dosch-Hebecker-Metz-Pirner. We relate these gluon distributions to the short and long distance behavior of the cross section of an adjoint dipole scattering off a proton. The leading order result is a constant, while the next-to-leading order result shows a 
enhancement at small x. To get numerical results for the gluon distributions at the initial scale Q
2
0 = 1.8 GeV2, we compute the adjoint dipole-proton cross section in the loop-loop correlation model. Quark distributions at the same initial scale are parameterized according to Regge theory. We evolve quark and gluon distributions to higher Q
2 values using the DGLAP equation and compute charm and proton structure functions in the small-x region for different Q
2 values.
© Springer-Verlag, 2004
