Low-scale Resonant Leptogenesis in $SU(5)$ GUT with $\mathcal{T}_{13}$ Family Symmetry

TL;DR

This paper explores low-scale resonant leptogenesis within an $SU(5) imes ext{T}_{13}$ model, linking high-energy CP phases to observable neutrino properties and analyzing the viable parameter space for neutrino masses and experimental detection.

Contribution

It introduces a novel $SU(5) imes ext{T}_{13}$ framework connecting high-energy CP phases to low-energy neutrino phenomena and identifies the parameter space compatible with leptogenesis and experimental constraints.

Findings

Lower bound on right-handed neutrino masses in the GeV range.

Existence of an upper TeV-scale bound on neutrino masses due to washout effects.

Potential detectability of some parameter space in future high-intensity experiments like DUNE.

Abstract

We investigate low-scale resonant leptogenesis in an $SU(5) \times \mathcal{T}_{13}$ 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 $\mathrm{GeV}$ range, where part of the parameter space, although in tension with Big Bang Nucleosynthesis constrains, can be probed in planned high intensity experiments like DUNE. We also find the existence of a curious upper bound ($\text{TeV}$-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.