AROMA 2.2 - A Monte Carlo Generator for Heavy Flavour Events in $ep$ Collisions
G. Ingelman, J. Rathsman, G. A. Schuler
TL;DR
AROMA 2.2 is a Monte Carlo generator for heavy-flavour production in $ep$ collisions, dominated by boson-gluon fusion with full electroweak structure and heavy-quark masses. It combines exact LO matrix elements with QCD parton showers and Lund hadronization to produce fully exclusive events, aided by Divonne-based importance sampling for efficient phase-space generation. While NLO results exist for inclusive distributions, AROMA relies on showering to model higher-order effects and discusses limitations and neglected processes such as intrinsic charm and resolved-photon contributions. The code is an add-on to LEPTO, interfacing with Jetset/PYTHIA and Divonne, and is released with dependencies and a demonstration workflow to enable heavy-flavour studies in $ep$ environments.
Abstract
A program to simulate the production of heavy quarks through the boson-gluon fusion process in $e^{\pm}p$ collisions is presented. The full electro\-weak structure of the electron--gluon interaction is taken into account as well as the masses of the produced heavy quarks. Higher order QCD radiation is treated using initial and final state parton showers, and hadronization is performed using the Lund string model. Physics and programming aspects are described in this manual.