A framework for second-order parton showers

TL;DR

This paper introduces a new framework for incorporating second-order perturbative corrections into parton shower simulations, improving their accuracy for modeling gluon emissions in particle physics.

Contribution

It presents a formalism that combines O(alphaS^2)-corrected kernels with tree-level kernels, enabling more precise modeling of radiation patterns in parton showers.

Findings

Developed an explicit implementation of 2->4 shower branchings.

Achieved a combined Sudakov evolution kernel accurate to O(alphaS^2).

Enhanced the theoretical foundation for next-to-leading order parton showers.

Abstract

A framework is presented for including second-order perturbative corrections to the radiation patterns of parton showers. The formalism allows to combine O(alphaS^2)-corrected iterated 2->3 kernels for "ordered" gluon emissions with tree-level 2->4 kernels for "unordered" ones. The combined Sudakov evolution kernel is thus accurate to O(alphaS^2). As a first step towards a full-fledged implementation of these ideas, we develop an explicit implementation of 2->4 shower branchings in this letter.