Constraining double parton correlations and interferences

TL;DR

This paper derives limits on interference double parton distributions in unpolarized protons, constraining the correlations and interferences between two partons, which are crucial for understanding double parton scattering at the LHC.

Contribution

It introduces new theoretical constraints on interference double parton distributions based on probability interpretation, reducing uncertainties in modeling double parton scattering.

Findings

Limits on interference DPDs derived from probability considerations

Constraints on correlations between two partons inside unpolarized protons

Implications for modeling double parton scattering at the LHC

Abstract

Double parton scattering (DPS) has become very relevant as a background to interesting analyses performed by the experiments at the LHC. It encodes knowledge of correlations between the proton constituents not accessible in single parton scattering. Within perturbative QCD DPS is described in terms of partonic subprocesses and double parton distributions (DPDs). There exists a large number of different DPDs describing the different possible states of two partons inside a proton. They include correlations between the two partons and interferences between the two hard subprocesses. Taking the probability interpretation of the DPDs as starting point, we derive limits on the interference DPDs and thereby constrain the size of correlations between two partons inside an unpolarized proton.