English

Predictive $S_4$ flavon model with $\text{TM}_1$ mixing and baryogenesis through leptogenesis

High Energy Physics - Phenomenology 2020-09-08 v3

Abstract

We use S4S_4 discrete group to construct a neutrino flavour model which leads to TM1TM_1 mixing and is consistent with the neutrino oscillation data. Using the model's constrained parameter space, we predict the values of Dirac CPCP phase and the light neutrino mass as 1<sinδ<0.9-1<\sin \delta <-0.9 and 1.7<m1(meV)<5.51.7<m_1 (\text{meV})<5.5 respectively. We thoroughly examine the usefulness of this model in explaining the observed baryon asymmetry of the Universe. Near-maximal breaking of CP symmetry (arising due to the TM1\text{TM}_1 constraint) helps us in generating adequate baryon asymmetry through leptogenesis. We study the evolution of the asymmetry (generated due to the decay of the heavy Majorana neutrinos) starting from the primordial Universe in two different ways (i)explicitly solving network of Boltzmann equations, (ii) using approximate analytic solution and we have shown the extent of their equivalence. Nearly accurate analytical fits are used thereafter to evaluate baryon asymmetry for the whole parameter space allowed by 3σ3\sigma global fit of oscillation data and to impose a constraint on the yet unbounded mass scale parameter of Dirac neutrino mass matrix. Furthermore, significant contribution of N2N_2 decay in the context of flavoured leptogenesis is also estimated.

Keywords

Cite

@article{arxiv.2003.00506,
  title  = {Predictive $S_4$ flavon model with $\text{TM}_1$ mixing and baryogenesis through leptogenesis},
  author = {Mainak Chakraborty and R. Krishnan and Ambar Ghosal},
  journal= {arXiv preprint arXiv:2003.00506},
  year   = {2020}
}

Comments

49 pages, 12 figures, two more subsections (Construction of the flavon potentials and CP asymmetry parameters in terms of Casas Ibarra parametrization) have been added in the appendix, version published in JHEP