Low-scale resonant leptogenesis in SU(5) GUT with T13 family symmetry.

We investigate low-scale resonant leptogenesis in an SU(5)×T13 model where a single high-energy phase in the complex tribimaximal seesaw mixing produces the yet to be observed low-energy Dirac and Majorana CP phases. A fourth right-handed neutrino, required to generate viable light neutrino masses within this scenario, also turns out to be necessary for successful resonant leptogenesis where CP asymmetry is produced by the same high-energy phase. We derive a lower bound on the right-handed neutrino mass spectrum in the GeV range, where part of the parameter space, although in tension with big bang nucleosynthesis constraints, can be probed in planned high-intensity experiments like DUNE. We also find the existence of a curious upper bound (TeV-scale) on the right-handed neutrino mass spectrum in majority of the parameter space due to significant washout of the resonant asymmetry by lighter right-handed neutrinos. While in most of the parameter space of our model classical Boltzmann equations are sufficient, when right-handed neutrino masses are below the electroweak sphalerons freeze-out temperature we resort to the more general density matrix formalism to take into account decays and oscillations of the right-handed neutrinos as well as their helicities which are relevant when they are relativistic. [ABSTRACT FROM AUTHOR]