Programme

O.9 -- Oral, VCTP-49

Date: Wednesday, 31 July 2024

Time: 15:05 - 15:30

Emergence of dark symmetry and neutrino mass scales from flavor symmetry.

Ranjeet Kumar, Newton Nath and Rahul Srivastava

Department of Physics, Indian Institute of Science Education and Research - Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, India.

We worked on a model for hybrid neutrino mass generation, wherein scotogenic dark sector particles, including dark matter, are charged non-trivially under the $A_4$ flavor symmetry. The spontaneous breaking of the $A_4$ group to the residual $Z_2$ subgroup results in the “cutting” of the radiative loop. As a consequence the neutrinos acquire mass through the hybrid “scoto-seesaw” mass mechanism, with the residual $Z_2$ subgroup ensuring the stability of the dark matter. The flavor symmetry also leads to several predictions including the normal ordering of neutrino masses and “generalized $\mu − \tau$ reflection symmetry” in leptonic mixing. Additionally, it gives testable predictions for neutrinoless double beta decay and a lower limit on the lightest neutrino mass. Finally, the model allows only scalar dark matter, whose mass has a theoretical upper limit of ∼ 600 GeV, with viable parameter space satisfying all dark matter constraints, available only up to about 80 GeV. Various aspects of this highly predictive framework can be tested in both current and upcoming neutrino and dark matter experiments.

Presenter: Ranjeet Kumar