Multi-partonic interactions, iterated discontinuities and the virtuality expansion in deep inelastic scattering

TL;DR

This paper develops a perturbative multi-parton interaction model for deep inelastic scattering, providing infrared-finite building blocks and applying them to next-to-leading order structure functions, with implications for scale dependence and scheme changes.

Contribution

Introduces a novel perturbative framework for multi-partonic interactions with infrared-finite components, applied to NLO structure functions in DIS.

Findings

Derived compact expressions for building blocks using double discontinuities.

Applied the model to compute NLO structure functions in DIS.

Discussed scale dependence and scheme change possibilities.

Abstract

We introduce a perturbative model that accounts for the contribution of multi-partonic interactions to collider observables. A key feature of this multi-parton model is that cross sections are organised in terms of building blocks that are separately infrared-finite in virtue of the KLN theorem. We find compact expressions for these building blocks in terms of double discontinuities of Feynman-type integrals obtained by endowing a vacuum graph with additional topological information. The framework is applied to the computation of next-to-leading order structure functions in deep inelastic scattering. We comment on the scale dependence of these structure functions and discuss the possibility of relating them by a scheme change to those computed in the parton model. Finally we lay down next steps for analogous computations for deep inelastic scattering at NNLO and Drell-Yan at NLO.