$\mu -\tau$ Reflection Symmetry Embedded in Minimal Seesaw

Abstract

We embed $\mu -\tau$ reflection symmetry into the minimal seesaw formalism, where two right-handed neutrinos are added to the Standard Model of particle physics. Assuming that both the left- and right-handed neutrino fields transform under $\mu -\tau$ reflection symmetry, we obtain the required forms of the neutrino Dirac mass matrix and the Majorana mass matrix for the right-handed neutrinos. To investigate the neutrino phenomenology at low energies, we first consider the breaking of $\mu -\tau$ reflection symmetry due to the renormalization group running, and then systematically study various breaking schemes by introducing explicit breaking terms at high energies.

Comments: 35 pages, 7 figures, 4 tables, Version accepted for publication in Eur. Phys. J. C