Low-Scale Leptogenesis with Low-Energy Dirac CP-Violation
| Autor: | Granelli, Alessandro, Pascoli, Silvia, Petcov, Serguey T. |
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| Rok vydání: | 2023 |
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| Zdroj: | Phys. Rev. D 108 (2023) L101302 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.108.L101302 |
| Popis: | We study the freeze-in scenario of leptogenesis via oscillations within the type-I seesaw model with two quasi-degenerate heavy Majorana neutrinos $N_{1,\,2}$ having masses $M_2 > M_1 \sim (0.1-100)\,\text{GeV}$, $(M_2-M_1)/M_1 \ll 1$, focusing on the role of the CP-violation provided by the Dirac phase $\delta$ of the Pontecorvo-Maki-Nakagawa-Sakata lepton mixing matrix. We find that viable leptogenesis can be due solely to CP-violating values of $\delta$ and that the $N_{1,\,2}$ total mixing squared $\Theta^2=\sum_\alpha\Theta^2_\alpha$ needed is within the reach of future experiments, $\Theta_\alpha$ parameterising the coupling to the charged lepton $\alpha=e,\,\mu,\,\tau$. Furthermore, the required parameter space differs from that associated with additional Casas-Ibarra sources of CP-violation. Future determination of $\delta$, $\Theta^2$ and/or the ratios $\Theta_\tau^2:\Theta^2_\mu:\Theta^2_e$ would provide a critical test of the considered scenario. Comment: 7 pages, 2 figures; matches version published in PRD |
| Databáze: | arXiv |
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