English

Leptogenesis in a Left-Right Symmetric Model with double seesaw

High Energy Physics - Phenomenology 2024-03-11 v2 High Energy Physics - Theory

Abstract

We explore the connection between low-scale CP-violating Dirac phase~(δ)(\delta) and high-scale leptogenesis in a Left-Right Symmetric Model (LRSM) with scalar bidoublet and doublets. The fermion sector of the model is extended with one sterile neutrino~(SL)(S_L) per generation to implement a double seesaw mechanism in the neutral fermion mass matrix. The double seesaw is performed via the implementation of type-I seesaw twice. The first seesaw facilitates the generation of Majorana mass term for heavy right-handed (RH) neutrinos~(NR)(N_R), and the light neutrino mass becomes linearly dependent on SLS_L mass in the second. In our framework, we have taken charge conjugation (CC) as the discrete left-right (LR) symmetry. This choice assists in deriving the Dirac neutrino mass matrix (MDM_D) in terms of the light and heavy RH neutrino masses and light neutrino mixing matrix UPMNSU_{PMNS} (containing δ\delta). We illustrate the viability of unflavored thermal leptogenesis via the decay of RH neutrinos by using the obtained MDM_D with the masses of RH neutrinos as input parameters. A complete analysis of the Boltzmann equations describing the asymmetry evolution is performed in the unflavored regime, and it is shown that with or without Majorana phases, the CP-violating Dirac phase is sufficient to produce the required asymmetry in the leptonic sector within this framework for a given choice of input parameters. Finally, we comment on the possibility of constraining our model with the current and near-future oscillation experiments, which are aimed at refining the value of δ\delta.

Keywords

Cite

@article{arxiv.2310.09337,
  title  = {Leptogenesis in a Left-Right Symmetric Model with double seesaw},
  author = {Utkarsh Patel and Pratik Adarsh and Sudhanwa Patra and Purushottam Sahu},
  journal= {arXiv preprint arXiv:2310.09337},
  year   = {2024}
}

Comments

45 pages, 13 figures, 5 Tables