Double parton scattering in double logarithm approximation of perturbative QCD

TL;DR

This paper develops a theoretical framework to understand double parton scattering (DPS) by analyzing single and double perturbative splitting diagrams within the double logarithm approximation of perturbative QCD. It expresses DPS cross sections in terms of generalized double parton distributions and evaluates the leading contributions from 1x1, 1x2, and 2x2 configurations, showing they share the same leading exponential behavior but differ in normalization. Through saddle-point analysis of gluon-dominated evolution, it clarifies when perturbative splittings enhance DPS and highlights the importance of two-scale processes as probes of double evolution, with possible implications for BFKL and DGLAP dynamics at the LHC. The findings inform DPS modeling and guide experimental strategies to disentangle perturbative correlations from nonperturbative effects, ultimately improving predictions for DPS backgrounds and signals at high-energy colliders.

Abstract

Using the explicit form of the known single distribution functions (the Green's functions) in the double logarithm approximation of perturbative QCD, we analyze the structure of splitting diagrams as a source of double parton perturbative correlations in the proton. The related phenomenological effects are discussed for the conditions of the LHC experiments.

Figures (1)

• Figure 1: The $q$ dependence of the integrand $f(L)$ in the logarithmic scale.