The Standard Model of Particle Physics with Diracian Neutrino Sector

• Main Author: Theodorus Maria Nieuwenhuizen
• Format: Article
• Language: English
• Published: MDPI AG 2019-08-01
• Series: Symmetry
• Subjects: standard model; sterile neutrinos; Majorana mass; pseudo Dirac neutrinos; ANITA
• Online Access: https://www.mdpi.com/2073-8994/11/8/994

The minimally extended standard model of particle physics contains three right handed or sterile neutrinos, coupled to the active ones by a Dirac mass matrix and mutually by a Majorana mass matrix. In the pseudo-Dirac case, the Majorana terms are small and maximal mixing of active and sterile states occurs, which is generally excluded for solar neutrinos. In a “Diracian” limit, the physical masses become pairwise degenerate and the neutrinos attain a Dirac signature. Members of a pair do not oscillate mutually so that their mixing can be undone, and the standard neutrino model follows as a limit. While two Majorana phases become physical Dirac phases and three extra mass parameters occur, a better description of data is offered. Oscillation problems are worked out in vacuum and in matter. With lepton number −1 assigned to the sterile neutrinos, the model still violates lepton number conservation and allows very feeble neutrinoless double beta decay. It supports a sterile neutrino interpretation of Earth-traversing ultra high energy events detected by ANITA.