PYTHIA 6.4 Physics and Manual

TL;DR

PYTHIA 6.4 is a comprehensive Monte Carlo event generator for simulating high-energy particle collisions, combining theoretical models and experimental data to produce realistic particle event sets for research in particle physics.

Contribution

This manual details the physics models, algorithms, and program structure of PYTHIA 6.4, enabling users to generate and analyze high-energy physics events with improved accuracy and customization.

Findings

Provides detailed physics modeling for a wide range of reactions

Includes extensive information on program components and customization options

Enhances the simulation of complex particle interactions

Abstract

The PYTHIA program can be used to generate high-energy-physics `events', i.e. sets of outgoing particles produced in the interactions between two incoming particles. The objective is to provide as accurate as possible a representation of event properties in a wide range of reactions, within and beyond the Standard Model, with emphasis on those where strong interactions play a role, directly or indirectly, and therefore multihadronic final states are produced. The physics is then not understood well enough to give an exact description; instead the program has to be based on a combination of analytical results and various QCD-based models. This physics input is summarized here, for areas such as hard subprocesses, initial- and final-state parton showers, underlying events and beam remnants, fragmentation and decays, and much more. Furthermore, extensive information is provided on all program elements: subroutines and functions, switches and parameters, and particle and process data. This should allow the user to tailor the generation task to the topics of interest.