A C++ particle data table interface

For some time, there has been a need for a C++ class embodying the information contained in the Review of Particle Properties(1). We have written HepPDT to fill this need. HepPDT allows access to particle name, particle ID, charge, nominal mass, total width, spin information, color information, constituent particles, and decay mode information. HepPDT is designed to be used by StdHepC++(2), HepMC(3), or any generated particle class. Generated particles will contain a pointer to the particle data information found in the HepPDT particle data table. HepPDT also has simple mechanisms to enable customized decay chains.