2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/51002A (M4 x M4) x Z4 model, describing an extended particle composed of two local modes and represented by a field psi(x, xi ;z), is formulated in its most general form (x, xi ; z) belong to (M4 x M4) x Z4. The 'z' argument specifies whether the particle is observable, unobservable, or partially observable (the latter case appears in two forms). In this four-sheeted structure, each sheet posses its own symmetry localized with respect to both space-times M4 inducing thereby connections in the continuous directions. Connections in the discrete direction describe transitions between observable, unobservable, and partially observable states. Curvatures and propagators are determined.15 pages, LaTeX; Subsections and e-mail Added, typos correctedHigh Energy Physics - TheoryOn interaction in extended particle model on (M4 x M4) x Z4text