Improvements on dipole shower colour

Author(s)
Jack Holguin, Jeffrey R. Forshaw, Simon Plätzer
Abstract

The dipole formalism provides a powerful framework from which parton showers can be constructed. In a recent paper (Forshaw et al. 2020), we proposed a dipole shower with improved colour accuracy and in this paper we show how it can be further improved. After an explicit check at O(αs2) we confirm that our original shower performs as it was designed to, i.e. inheriting its handling of angular-ordered radiation from a coherent branching algorithm. We also show how other dipole shower algorithms fail to achieve this. Nevertheless, there is an O(αs2) topology where it differs at sub-leading Nc from a coherent branching algorithm. This erroneous topology can contribute a leading logarithm to some observables and corresponds to emissions that are ordered in kt but not angle. We propose a simple, computationally efficient way to correct this and assign colour factors in accordance with the coherence properties of QCD to all orders in αs.

Organisation(s)
Particle Physics
External organisation(s)
University of Manchester
Journal
European Physical Journal C
Volume
81
No. of pages
16
ISSN
1434-6044
DOI
https://doi.org/10.1140/epjc/s10052-021-09145-1
Publication date
04-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
103036 Theoretical physics, 103012 High energy physics, 103034 Particle physics
ASJC Scopus subject areas
Engineering (miscellaneous), Physics and Astronomy (miscellaneous)
Portal url
https://ucris.univie.ac.at/portal/en/publications/improvements-on-dipole-shower-colour(2c047d4b-447c-430a-ae3c-1ff786c5e866).html