Disentangling correlations in Multiple Parton Interactions

TL;DR

This paper explores methods to disentangle different types of parton correlations in high-energy collisions, enhancing understanding of hadron structure by analyzing double parton interactions in proton-deuteron collisions.

Contribution

It introduces a novel approach to separate longitudinal and transverse parton correlations using data from proton-deuteron collisions.

Findings

Correlations in parton distributions can be isolated by selecting specific final states.

Double parton interactions provide additional information to distinguish correlation types.

Effective cross section values are influenced by both spatial proximity and multiplicity dispersion.

Abstract

Multiple Parton Interactions are the tool to obtain information on the correlations between partons in the hadron structure. Partons may be correlated in all degrees of freedom and all different correlation terms contribute to the cross section. The contributions due to the different parton flavors can be isolated, at least to some extent, by selecting properly the final state. In the case of high energy proton-proton collisions, the effects of correlations in the transverse coordinates and in fractional momenta are, on the contrary, unavoidably mixed in the final observables. The standard way to quantify the strength of double parton interactions is by the value of the effective cross section and a small value of the effective cross section may be originated both by the relatively short transverse distance between the pairs of partons undergoing the double interaction and by a large dispersion of the distribution in multiplicity of the multi-parton distributions. The aim of the present paper is to show how the effects of longitudinal and transverse correlations may be disentangled by taking into account the additional information provided by double parton interactions in high energy proton-deuteron collisions.