Relating leptogenesis parameters to light neutrino masses

We obtain model independent relations among neutrino masses and leptogenesisparameters. We find exact relations that involve the CP asymmetries$\epsilon_{N_\alpha}$, the washout parameters $\tilde m_\alpha$ and$\theta_{\alpha\beta}$, and the neutrino masses $m_i$ and $M_\alpha$, as wellas powerful inequalities that involve just $\tilde m_\alpha$ and $m_i$. Weprove that the Yukawa interactions of at least two of the heavy singletneutrinos are in the strong washout region ($\tilde m_\alpha\gg10^{-3} eV$).Comment: 5 pages, 1 figur