Softly Broken Hidden Symmetry in Every Renormalizable Field Theory

Abstract

It is pointed out that every renormalizable field theory has a symmetry which is hidden in plain sight. In all practical cases, it is also broken softly, either explicitly or spontaneously. The soft explicit breaking mass terms may be assumed naturally small compared to the scalar mass-squared terms. Implications for extensions of the standard model are discussed. New left-right model of two-loop radiative Dirac neutrino mass is proposed.

Comments: 9 pages, 2 figures, text expanded, references added, version to appear in Nucl. Phys. B