CHARGED NEUTRINOS?

Abstract

If right-handed neutrinos are added to the Standard Model (SM), then the charge assignments of the quarks and leptons are not fixed by anomaly cancellation, but depend on a free continuous parameter. Thus if right-handed neutrinos exist then it is possible that there also exist small deviations from the canonical assignments of the electric charge, leading to charged neutrinos and neutrons. Experiment is used to limit this parameter. It is pointed out that a nearly massless neutrino with a small charge may nonetheless have large tree-level and anomalous magnetic moments. Ways that the SM might be extended to yield charged neutrinos are indicated.