Lepton flavour symmetry and the neutrino magnetic moment |
| |
Authors: | G Ecker W Grimus |
| |
Institution: | 1. Institut für Theoretische Physik, Universit?t Wien, Boltzmanngasse 5, A-1090, Wien, Austria
|
| |
Abstract: | With the standard model gauge group and the three standard left-handed Weyl neutrinos, two minimal scenarios are investigated where an arbitrary non-Abelian lepton flavour symmetry groupG
H
is responsible for a light neutrino with a large magnetic moment. In the first case, with scalar fields carrying lepton flavour, some finetuning is necessary to get a small enough neutrino mass for
v
=O(10)–11
B. In the second scenario, the introduction of heavy charged gauge singlet fermions with lepton flavour allows for a strictly massless neutrino to one-loop order. In both cases, the interference mechanism for smallm
and large
v
is unique, independently ofG
H
. In explicit realizations of the two scenarios, the horizontal groups are found to be non-Abelian extensions of a Zeldovich-Konopinski-Mahmoud lepton number symmetry. Only a discrete part ofG
H
is spontaneously broken leading to a light Dirac neutrino with a large magnetic moment. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|