A generalization of the well-known Georgi-Jarlskog relation $\left(m_{\mu }/m_{\tau }\right)=3\mathrm{}\left(m_s/m_b\right)$ to neutrinos is found in the context of $\mathrm{SO}\left(10\right)$. This new relation is $\left(m_{{\nu }_{\mu }}/m_{{\nu }_{\tau }}\right)=16\mathrm{}\left(m_c/m_t\right)$, which is consistent with present data, assuming the Mikheyev-Smirnov-Wolfenstein solution to the solar neutrino problem.

• Received 27 April 2000

DOI:https://doi.org/10.1103/PhysRevLett.85.1170