Tau and muon pair production cross-sections in electron-positron annihilations at sqrt{s} = 10.58 GeV

The calculational precision of $\text{ee}\to \text{tautau}$ and $\text{ee}\to \text{mumu}$ production cross-sections in electron-positron annihilations at \roots = 10.58 \gev are studied for the \kk Monte Carlo simulation program. We determine $\sigma (\text{ee}\to \text{tautau})=(0.919\pm 0.003)\text{nb}$ and $\sigma(\ee\to\mumu) = (1.147 \pm 0.005) \nb$, where the error represents the precision of the calculation.