Precise determination ofsin2θWand the masses of weak vector bosons in SU(5)

Abstract

The measurement of the masses $m_W$ and $m_Z$ of the weak vector bosons $W$ and $Z$ will provide an accurate determination of the mixing angle ${\theta }_W$. With this in view, precise theoretical values of ${{sin}^2\theta }_W$, $m_W$, and $m_Z$ in the grand unified guage theory based on SU(5) with three fermion families are given.