Oct 2016 - Sep 2017

Lepton Number Violation in the Type I Seesaw Framework

by Kristian Moffat (IPPP)

Friday, 10 March 2017 from to (Europe/London)
at IPPP ( OC218 )
A purely type I seesaw extension of the Standard Model will be considered in the context of lepton number violation (LNV). The most general scheme by which the light neutrino masses arise from a cancellation of scales (rather than a suppression by large scales) will be developed. Within this scheme the usual scaling arguments no longer hold and consequently the question of the observability of LNV in experiments must be reconsidered. The tree-level conditions for lepton number conservation (LNC) will be derived. It is shown that the neutrinos either decouple from active leptons or that they form Dirac pairs.  This will be followed by a discussion of one-loop corrections. These present an important qualitative deviation from tree-level results due to their intermixing of previously independent parameters.