Abstract
The formulation of manifestly covariant relativistic statistical mechanics as the description of an ensemble of events in spacetime parametrized by an invariant proper-time τ is reviewed. The linear and cubic mass spectra, which result from this formulation (the latter with the inclusion of anti-events) as the actual spectra of an individual hadronic multiplet and hot hadronic matter, respectively, are discussed. These spectra allow one to predict the masses of particles nucleated to quasi-levels in such an ensemble. As an example, the masses of the ground-state mesons and baryons are considered; the results are in excellent agreement with the measured hadron masses. Additivity of inverse Regge slopes is established and shown to be consistent with available experimental data on the D meson and Λc baryon production