A predictive SO(10) scheme for fermion masses and mixings

We present a predictive scheme for fermion masses and mixings inspired by supersymmetric SO(10) in which the gauge hierarchy problem is resolved without fine tuning the parameters. There are six predictions in the flavor sector, all consistent with the present data. The scheme reproduces the familiar asymptotic relations mb = mτ and mdmsmb = memμmτ. A new expression for Vcb is obtained in terms of the quark masses. The remaining predictions involve the quark mixing angles Vus and Vub, as well as the parameter tan β which turns out to be close to mtmb.