General Conditions for Lepton Flavour Violation at Tree- and 1-Loop Level

Abstract

In this work, we compile the necessary and sufficient conditions a theory has to fulfill in order to ensure general lepton flavour conservation, in the spirit of the Glashow-Weinberg criteria for the absence of flavour-changing neutral currents. At tree-level, interactions involving electrically neutral and doubly charged bosons are investigated. We also investigate flavour changes at 1-loop level. In all cases we find that the essential theoretical requirements can be reduced to a few basic conditions on the particle content and the coupling matrices. For 1-loop diagrams, we also investigate how exactly a GIM-suppression can occur that will strongly reduce the rates of lepton flavour violating effects even if they are in principle present in a certain theory. In all chapters, we apply our criteria to several models which can in general induce lepton flavour violation, e.g. LR-symmetric models or the MSSM. In the end we give a summarizing table of the obtained results, thereby demonstrating the applicability of our criteria to a large class of models beyond the Standard Model.

31 pages, 2 figures

References in corpus (5)

• Unitarity of the Leptonic Mixing Matrix
• A Survey of Lepton Number Violation Via Effective Operators
• Flavor Changing Neutral Current Effects and CP Violation in the Minimal 3-3-1 Model
• Lepton Flavour Violating tau Decays in the Left-Right Symmetric Model
• Static quantities of a neutral bilepton in the 331 model with right-handed neutrinos

Cited by in corpus (4)

• Lepton Flavour Violating Decays tau to lll and mu to e gamma in the Higgs Triplet Model
• Confronting Flavour Symmetries and extended Scalar Sectors with Lepton Flavour Violation Bounds
• Intrinsic flavor violation for massive neutrinos
• Lepton Flavor Violation in the LHT - A Clear Distinction from Supersymmetry