A three-parameter model for the neutrino mass matrix

Autor(en)
Walter Grimus, Luis Lavoura
Abstrakt

Using the type-II seesaw mechanism with three Higgs doublets phi(alpha) (alpha = e, mu, tau) and four Higgs triplets, we build a model for lepton mixing based on a 384-element horizontal symmetry group, generated by the permutation group S-3 and by six Z(2) transformations. The charged- lepton mass matrix is diagonal; the symmetries of the model would require all the three masses ma to be equal, but different vacuum expectation values of fa allow m(alpha) to split. The number of parameters in the Majorana neutrino mass matrix M-v depends on two options: full breaking of the permutation group S-3, or leaving mu-t interchange symmetry intact, and hard or spontaneous violation of CP. We discuss in detail the case with the minimal number of three parameters, wherein M-v is real, symmetric under mu-tau interchange and has equal diagonal elements. In that case, CP is conserved in lepton mixing, atmospheric neutrino mixing is maximal and theta(13) = 0; moreover, the type of neutrino mass spectrum and the absolute neutrino mass scale are sensitive functions of the solar mixing angle.

Organisation(en)
Teilchenphysik
Externe Organisation(en)
Universidade Técnica de Lisboa
Journal
Journal of Physics G: Nuclear and Particle Physics
Band
34
Seiten
1757-1769
Anzahl der Seiten
13
ISSN
0954-3899
DOI
https://doi.org/10.1088/0954-3899/34/7/014
Publikationsdatum
2007
Peer-reviewed
Ja
ÖFOS 2012
103036 Theoretische Physik
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/a-threeparameter-model-for-the-neutrino-mass-matrix(9be06a22-59e2-48bd-a4a0-07ddc3ea7f64).html