Initial-state showering based on colour dipoles connected to incoming parton lines

TL;DR

This paper introduces a new parton-shower model based on QCD dipoles that connects initial and final states, extending existing models to better simulate hadronic collision processes.

Contribution

It develops a novel initial-state showering model using colour dipoles linked to incoming partons, expanding the dipole radiation pattern to initial-state QCD radiation.

Findings

Encouraging results in electron-positron annihilation simulations

Effective modeling of Drell-Yan lepton-pair production

Improved QCD jet production predictions

Abstract

A parton-shower model for hadronic collisions based on the emission properties of QCD dipoles is proposed. This proposal therefore extends the well-known radiation pattern of pure final-state colour dipoles to QCD initial-state radiation, both of which are treated perturbatively. Corresponding dipole splitting functions are derived and the kinematics of all dipole splittings is discussed. Application to hadron production in electron-positron annihilation, to Drell-Yan lepton-pair and QCD jet production yields encouraging results.