Double parton correlations versus factorized distributions

Abstract

Using the generalized Lipatov-Altarelli-Parisi-Dokshitzer equations for the two-parton distribution functions we show numerically that the dynamical correlations contribute to these functions quite a lot in comparison with the factorized components. At the scale of CDF hard process ($\sim 5$ GeV) this contribution to the double gluon-gluon distribution is nearly 10% and increases right up to 30% at the LHC scale ($\sim 100$ GeV) for the longitudinal momentum fractions $x \leq 0.1$ accessible to these measurements. For the finite longitudinal momentum fractions $x \sim 0.2 ÷0.4$ the correlations are large right up to 90% in accordance with the predicted QCD asymptotic behaviour.

Figures (1)

• Figure 1: The ratio of perturbative QCD correlations to the factorized component for the double gluon-gluon distribution in the proton as a function of $x = x_1 = x_2$ for three values of $Q$ = 5(solid), 100(dashed), 250(dash-dotted) GeV.