https://doi.org/10.1140/epjc/s10052-017-5348-x
Regular Article - Theoretical Physics
Predictions for the neutrino parameters in the minimal gauged
model
1
Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo, 133–0033, Japan
2
Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), University of Tokyo, Kashiwa, 277–8583, Japan
* e-mail: asai@hep-th.phys.s.u-tokyo.ac.jp
Received:
28
September
2017
Accepted:
1
November
2017
Published online:
14
November
2017
We study the structure of the neutrino-mass matrix in the minimal gauged model, where three right-handed neutrinos are added to the Standard Model in order to obtain non-zero masses for the active neutrinos. Because of the
gauge symmetry, the structure of both Dirac and Majorana mass terms of neutrinos is tightly restricted. In particular, the inverse of the neutrino-mass matrix has zeros in the
and
components, namely, this model offers a symmetric realization of the so-called two-zero-minor structure in the neutrino-mass matrix. Due to these constraints, all the CP phases – the Dirac CP phase
and the Majorana CP phases
and
– as well as the mass eigenvalues of the light neutrinos
are uniquely determined as functions of the neutrino mixing angles
,
, and
, and the squared mass differences
and
. We find that this model predicts the Dirac CP phase
to be
–
(
–
), the sum of the neutrino masses to be
–0.22 eV (0.12–0.40 eV), and the effective mass for the neutrinoless double-beta decay to be
–0.055 eV (0.017–0.12 eV) at
(
) level, which are totally consistent with the current experimental limits. These predictions can soon be tested in future neutrino experiments. Implications for leptogenesis are also discussed.
© The Author(s), 2017