ISAJET 7.40: A Monte Carlo Event Generator for $pp, \bar pp$, and $e^+e^-$ Reactions

TL;DR

ISAJET 7.40 provides a comprehensive Monte Carlo event generator for high-energy pp, p pbar, and e+e- reactions, integrating perturbative QCD with phenomenological fragmentation and beam-jet modeling. The paper details the physics modules (hard scattering, QCD radiation, fragmentation, and beam jets), the SUSY extensions (MSSM, SUGRA, GMSB), and the full machinery for event generation, input control, and output. It also introduces new features for 7.40, including W+H/Z+H production and non-minimal GMSB, while documenting extensive version-history updates, patch organization, and practical usage across platforms. The work enables detailed collider phenomenology studies, including Higgs, SUSY, and technicolor signatures, with configurable PDFs, polarization, and higher-order process scaffolding, albeit within a leading-log QCD framework. Overall, ISAJET remains a versatile tool for simulating a wide range of high-energy processes and SUSY scenarios used in collider physics analyses.

Abstract

ISAJET is a Monte Carlo program which simulates $pp, \bar pp$ and $e^+e^-$ interactions at high energies. This document summarizes the physics underlying the program and describes how to use it. New features of Version 7.40 include generation of $W+H$ and $Z+H$ events, non-minimal GMSB models, and use of the experimental $α_s(M_Z)$ by default.