From Fermion Mass Matrices to Neutrino Oscillations

Abstract

We present an ansatz for the quark and lepton mass matrices, derivable from SO(10) type GUTs, which accommodates a heavy $(>92GeV)$ top quark and permits large mixings in the ${\nu }_{\mu }\leftrightarrow {\nu }_{\tau }$ sector (as suggested by the recent Kamiokande and IMB data on the atmospheric neutrinos). The well known asymptotic relations $m_b=m_{\tau }$, $m_s=\frac{1}{3}{m}_{\mu }$ and $m_d{m}_s=m_e{m}_{\mu }$ all hold to a good approximation. Depending on ${\nu }_{\mu }\leftrightarrow {\nu }_{\tau }$ mixing which can even be maximal, the mixing angle relevant for solar neutrino oscillation lies in the range $7.8\times 10^{-3}\stackrel{{}_{<}}{{}_{\sim }}{\sin }^{2}2{\theta }_{e\mu }\stackrel{{}_{<}}{{}_{\sim }}2.1\times 10^{-2}$. For the ${}^{71}$Ga experiment the event rate, normalized against the standard solar model prediction of 132 SNU, is estimated to be between 80 and 20 SNU.

Comments: 16 pages, in LaTeX