Interplay of soft and perturbative correlations in multiparton interactions at central rapidities

TL;DR

This paper investigates how soft and perturbative correlations influence multi-parton interactions at collider experiments, finding that soft correlations are negligible for high transverse momenta but significant at lower energies, with implications for understanding underlying events.

Contribution

It provides a detailed analysis of soft correlations' impact on multi-parton interactions, highlighting their relevance at different energy scales and for various experimental measurements.

Findings

Soft correlations are negligible for high transverse momentum regimes.

Soft correlations may significantly affect underlying event measurements.

The scale where soft correlations matter increases as x decreases, leading to stable ext{eff}_s at small x.

Abstract

We study the role of soft/nonperturbative correlations in the multi parton interactions in the central kinematics relevant for double parton scattering (DPS) and underlying event (UE) measurements at ATLAS and CMS. We show that the effect of soft correlations is negligible for DPS regime (typical transverse momenta larger than 10-20 GeV), but may be important for UE (several GeV scale). The characteristic scale where soft correlations become important increases with decrease of $x$ (energy increase) leading to approximately constant \effs at small x.