New Partial Symmetries from Group Algebras for Lepton Mixing

Abstract EN

Recent stringent experiment data of neutrino oscillations induces partial symmetries such as Z2 and Z2×CP to derive lepton mixing patterns.

New partial symmetries expressed with elements of group algebras are studied.

A specific lepton mixing pattern could correspond to a set of equivalent elements of a group algebra.

The transformation which interchanges the elements could express a residual CP symmetry.

Lepton mixing matrices from S3 group algebras are of the trimaximal form with the μ−τ reflection symmetry.

Accordingly, elements of S3 group algebras are equivalent to Z2×CP.

Comments on S4 group algebras are given.

The predictions of Z2×CP broken from the group S4 with the generalized CP symmetry are also obtained from elements of S4 group algebras.