Do Small-Mass Neutrinos Participate in Gauge Transformations?
2016 (English)In: Advances in High Energy Physics, ISSN 1687-7357, E-ISSN 1687-7365, 1-7 p., 1847620Article in journal (Refereed) Published
Neutrino oscillation experiments presently suggest that neutrinos have a small but finite mass. If neutrinos have mass, there should be a Lorentz frame in which they can be brought to rest. This paper discusses how Wigner’s little groups can be used to distinguish between massive and massless particles. We derive a representation of the SL(2,c) group which separates out the two sets of spinors: one set is gauge dependent and the other set is gauge invariant and represents polarized neutrinos. We show that a similar calculation can be done for the Dirac equation. In the large-momentum/zero-mass limit, the Dirac spinors can be separated into large and small components. The large components are gauge invariant, while the small components are not. These small components represent spin-1/2 non-zero-mass particles. If we renormalize the large components, these gauge invariant spinors represent the polarization of neutrinos. Massive neutrinos cannot be invariant under gauge transformations.
Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2016. 1-7 p., 1847620
IdentifiersURN: urn:nbn:se:kth:diva-189756DOI: 10.1155/2016/1847620OAI: oai:DiVA.org:kth-189756DiVA: diva2:948742
QC 201607132016-07-132016-07-132016-07-21Bibliographically approved