Resonance- and Width-aware Parton Shower Evolution and NLO Matching

TL;DR

This paper presents a novel NLO simulation technique for $e^+e^- o W^+W^-bar{b}$ that accurately models resonance effects and finite width corrections, with a publicly available implementation.

Contribution

It introduces a resonance- and width-aware parton shower evolution and NLO matching method, extending beyond traditional Breit-Wigner resonance models.

Findings

First phenomenological results for future electron-positron colliders.

A publicly available simulator based on ALARIC and SHERPA.

Enhanced modeling of finite width effects in resonance regions.

Abstract

We introduce a technique for the next-to-leading order accurate simulation of $e^+e^-\to W^+W^-b\bar{b}$ that respects the resonant nature of the process above and near the top-quark pair production threshold. The parton-shower evolution, infrared subtraction and NLO matching account in particular for finite width effects beyond the Breit-Wigner structure considered in resonance-aware approaches. We present first phenomenological results relevant to a potential future electron-positron collider and provide a publicly available simulator based on the ALARIC parton shower and the SHERPA event generator.