D14 - A Common Origin of the Cabibbo Angle and the Lepton Mixing Angle theta^l_13

TL;DR

This paper extends a supersymmetric D14 flavor symmetry model to the lepton sector, explaining the origin of the lepton mixing angle theta^l_13 and its relation to the Cabibbo angle through subgroup mismatches.

Contribution

It introduces a D14-based model that links quark and lepton mixing angles via subgroup mismatches, providing a unified flavor symmetry explanation.

Findings

Lepton mixing angle theta^l_13 naturally fits experimental data.

The model reproduces the charged lepton mass hierarchy.

Next-to-leading order corrections only slightly alter the results.

Abstract

It has been shown that the Cabibbo angle can be predicted in terms of group theoretical quantities, if the dihedral group D14 plays the role of a flavor symmetry. We extend a supersymmetric D14 model to the lepton sector and show that theta^nu_13 and the deviation of theta^nu_23 from maximal mixing in the neutrino sector originate, similar to the Cabibbo angle in the quark sector, from a mismatch of different subgroups of D14 and are of the size of the Cabibbo angle. The mixing angles in the charged lepton sector are small. Thus, the lepton mixing angle theta^l_13 is naturally in its experimentally preferred range and theta^l_23 within its 3 sigma range. The solar mixing angle is of order one and the charged lepton mass hierarchy is correctly reproduced. Leading order results are only slightly perturbed, if next-to-leading order corrections are taken into account.