Leptogenesis in an SU(5) x A5 Golden Ratio Flavour Model: Addendum

TL;DR

This paper confirms previous approximate calculations of baryon asymmetry in an SU(5) x A5 flavour model, refining the results with detailed Boltzmann equation solutions and discussing implications for neutrino observables.

Contribution

It provides a detailed Boltzmann equation analysis of leptogenesis in a specific flavour model, validating earlier approximate results and updating predictions for neutrino observables.

Findings

Approximate results on baryon asymmetry are accurate within 20-30%.

Predicted neutrinoless double beta decay mass range is 3.3-14.3 meV.

Model predictions for low-energy neutrino observables remain stable.

Abstract

We derive and discuss the solution of the Boltzmann equations for leptogenesis in a phenomenologically viable SU(5) x A5 golden ratio flavour model proposed in arXiv:1410.2057 [hep-ph], arXiv:1502.00110 [hep-ph] . The model employs, in particular, the seesaw mechanism of neutrino mass generation. We find that the results on the baryon asymmetry of the Universe, obtained earlier in arXiv:1502.00110 [hep-ph] using approximate analytic expressions for the relevant CP violating asymmetry and efficiency factors, are correct, as was expected, up to 20-30 %. The phenomenological predictions for the low energy neutrino observables, derived using values of the parameters of the model for which we reproduce the observed value of the baryon asymmetry, change little with respect to those presented in arXiv:1502.00110 [hep-ph]. Among the many predictions of the model we find, for instance, that the neutrinoless double beta decay effective Majorana mass m_ee lies between 3.3 meV and 14.3 meV.