HepMC3

HepMC3 is a C++ object-oriented event record class library designed for high-energy physics. It provides a standardized way to represent and store the output of Monte Carlo event generators, which simulate particle collisions. The library facilitates the exchange of event data between different generators and analysis programs. Its core component is the HepMC event object, which contains a list of particles, their properties (such as momentum, mass, and charge), and their decay products. HepMC3 builds upon the foundation of its predecessor, HepMC2, introducing improvements in data structures, performance, and extensibility. It supports various output formats, including plain text files and the ROOT format, commonly used in particle physics. The library is widely adopted in the high-energy physics community and is essential for many research projects at facilities like CERN. Its design emphasizes ease of use for physicists and flexibility for developers working with complex simulation workflows. HepMC3 is released under the GNU General Public License.