2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90468We consider the use of the energy density for describing a localization of relativistic particles. This method is consistent with the causality requirements. The related positive operator valued measure is presented. The probability distributions for one particle states are given explicitly.RevTex 4, 4 pagesQuantum PhysicsHigh Energy Physics - Theorytext