2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/199234It is generally assumed that the physical vacuum of particle physics should be characterized by an energy momentum tensor in such a way to preserve exact Lorentz invariance. On the other hand, if the ground state were characterized by its energy-momentum vector, with zero spatial momentum and a non-zero energy, the vacuum would represent a preferred frame. Since both theoretical approaches have their own good motivations, we propose an experimental test to decide between the two scenarios.12 pages, no figuresHigh Energy Physics - Phenomenologytext