Unparticle as a particle with arbitrary mass

Abstract

The unparticle field operator can be expanded in terms of creation and destruction operators corresponding to particles with a continuous mass spectrum. Hence, when the 4-momentum of an unparticle is measured, then the unparticle manifests as an ordinary particle with a definite (but arbitrary) mass.

Comments: 5 pages, revised, to appear in Mod. Phys. Lett. A