Leptogenesis implications of two-zero textures of Majorana neutrino mass matrix in type-I seesaw model

Abstract

The type-I seesaw model with two-zero textures of the Majorana mass matrix for the right-handed neutrinos $M^{}_{\rm R}$ provides a highly predictive framework for neutrino mass generation and baryon asymmetry of the Universe via leptogenesis. In this work, we systematically investigate the compatibility of viable two-zero textures of $M^{}_{\rm R}$ with leptogenesis within the type-I seesaw scenario. We consider both a general diagonal Dirac neutrino mass matrix $M^{}_{\rm D}$ and two theoretically motivated special cases, namely the SO(10) GUT-inspired $M^{}_{\rm D} \sim \mathrm{diag}(m_u,m_c,m_t)$ and the flavor symmetry-induced $M^{}_{\rm D} \propto I$. Our study shows that two-zero textures of $M^{}_{\rm R}$ yield strong correlations between neutrino parameters and leptogenesis, offering distinctive phenomenological implications for neutrino flavor physics and baryon asymmetry of the Universe.

Figures (5)

• Figure 1: For the five experimentally allowed two-zero cofactor classes of $M^{}_\nu$ studied in section 2, their predictions for the lightest neutrino mass ($m^{}_1$/$m^{}_3$ in the NO/IO case) and $\delta$.
• Figure 2: For the five experimentally allowed two-zero cofactor classes of $M^{}_\nu$ studied in section 2, their predictions for the Majorana CP phases $\rho$ and $\sigma$.
• Figure 3: For the five experimentally allowed two-zero textures of $M^{}_{\rm R}$ studied in section 2, their predictions for the lightest right-handed neutrino mass $M^{}_1$ as functions of $r^{}_3$ for some benchmark values of $r^{}_2$.
• Figure 4: For the five experimentally allowed two-zero textures of $M^{}_{\rm R}$ studied in section 2, the allowed values of $Y^{}_{\rm B}$ as functions of $k$ for $r^{}_2$ and $r^{}_3$ in the range 0.1$-$10. The blue horizontal line stands for the observed value of $Y^{}_{\rm B}$.
• Figure 5: For the five experimentally allowed two-zero textures of $M^{}_{\rm R}$ studied in section 2, the values of $r^{}_2$ versus $r^{}_3$ that lead to successful leptogenesis for several benchmark values of $k$.