Sudakov evolution without unitarity

Abstract We present a method for sampling singular functions defined on (nested) multiparticle phase spaces, based on a generalisation of parton-shower phase-space generation techniques. At the heart of the method are three key ingredients: (1) the Sudakov sampling by which shower-style calculations...

Full description

Saved in:
Bibliographic Details
Main Authors: J. Altmann, H. T. Li, L. Scyboz, P. Skands
Format: Article
Language:English
Published: SpringerOpen 2025-08-01
Series:European Physical Journal C: Particles and Fields
Online Access:https://doi.org/10.1140/epjc/s10052-025-14576-1
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract We present a method for sampling singular functions defined on (nested) multiparticle phase spaces, based on a generalisation of parton-shower phase-space generation techniques. At the heart of the method are three key ingredients: (1) the Sudakov sampling by which shower-style calculations sweep across phase space in an ordered manner, from hard to soft; (2) the sequential nesting of multiparticle phase spaces; and (3) the factorisations obeyed by singular multiparton amplitudes on the edges of these phase spaces. We demonstrate a C++ implementation of the proposed algorithm, dubbed Sunshine   (loosely derived from Sudakov Nesting of Hard Integrals), for hadronic Z decays, and use it to test the tree-level accuracy of the Vincia sector shower through $$\mathcal{O}(\alpha _s^2)$$ O ( α s 2 ) . Graphic Abstract
ISSN:1434-6052