Decay: A Monte Carlo library for the decay of a particle with ROOT compatibility

TL;DR

Decay is a versatile Monte Carlo library compatible with ROOT, designed for simulating complex particle decay processes and integrating matrix elements over phase space, demonstrated through Standard Model Higgs decay examples.

Contribution

We introduce a general-purpose, ROOT-compatible Monte Carlo library for simulating multi-particle decays and integrating matrix elements, enhancing flexibility and usability in particle physics simulations.

Findings

Successfully generated decay kinematics for various processes.

Validated results against literature benchmarks.

Demonstrated application to Higgs boson decay into four leptons.

Abstract

Recently, there is a need for a general-purpose event generator of decays of an elementary particle or a hadron to a state of higher multiplicity ($N > 2$) that is simple to use and universal. We present the structure of such a library to produce generators that generate kinematics of decay processes and can be used to integrate any matrix element squared over phase space of this decay. Some test examples are presented, and results are compared with results known from the literature. As one of examples we consider the Standard Model Higgs boson decay into four leptons. The generators discussed here are compatible with the ROOT interface.