Relating leptogenesis parameters to light neutrino masses

Abstract

We obtain model independent relations among neutrino masses and leptogenesis parameters. We find exact relations that involve the CP asymmetries ${ϵ}_{N_{\alpha }}$, the washout parameters ${\tilde{m}}_{\alpha }$ and ${\theta }_{\alpha \beta }$, and the neutrino masses $m_i$ and $M_{\alpha }$, as well as powerful inequalities that involve just ${\tilde{m}}_{\alpha }$ and $m_i$. We prove that the Yukawa interactions of at least two of the heavy singlet neutrinos are in the strong washout region (${\tilde{m}}_{\alpha }\gg 10^{-3}eV$).

Comments: 5 pages, 1 figure