Relativistic particle systems with confining interactions

A restricted case of a relativistic Hamiltonian particle dynamics is discussed here, the restriction referring to conditions on the interaction. This case permits center-of-momentum variables as well as individual particle variables. The latter satisfy a covariant canonical algebra. It also permits observable world lines and a CM position which is the energy average of the particle positions. The Todorov-Komar formulation emerges as a special case when a suitable gauge is used.