Event generation with SHERPA 1.1

TL;DR

Sherpa 1.1 is a versatile Monte Carlo event generator for simulating high-energy particle collisions, integrating matrix elements, parton showers, multiple interactions, and decay models for comprehensive collider event analysis.

Contribution

The paper introduces Sherpa 1.1, which combines advanced matrix-element calculations with parton showers and decay models, offering a flexible and comprehensive simulation framework.

Findings

Includes a flexible tree-level matrix-element generator.

Employs Catani-Krauss-Kuhn-Webber approach for multi-parton merging.

Provides detailed modeling of hadronization and decay processes.

Abstract

In this paper the current release of the Monte Carlo event generator Sherpa, version 1.1, is presented. Sherpa is a general-purpose tool for the simulation of particle collisions at high-energy colliders. It contains a very flexible tree-level matrix-element generator for the calculation of hard scattering processes within the Standard Model and various new physics models. The emission of additional QCD partons off the initial and final states is described through a parton-shower model. To consistently combine multi-parton matrix elements with the QCD parton cascades the approach of Catani, Krauss, Kuhn and Webber is employed. A simple model of multiple interactions is used to account for underlying events in hadron--hadron collisions. The fragmentation of partons into primary hadrons is described using a phenomenological cluster-hadronisation model. A comprehensive library for simulating tau-lepton and hadron decays is provided. Where available form-factor models and matrix elements are used, allowing for the inclusion of spin correlations; effects of virtual and real QED corrections are included using the approach of Yennie, Frautschi and Suura.