Answer
$8\times10^{-27}s $
Work Step by Step
Estimate the lifetime of the virtual W particle by using the Heisenberg uncertainty principle, equation 28–2.
$$\Delta E \approx \frac{\hbar}{\Delta t}$$
$$\Delta t \approx \frac{\hbar}{\Delta E}$$
$$=\frac{1.055\times 10^{-34}J \cdot s}{80.385\times10^9eV}\frac{1eV}{1.60\times10^{-19}J}$$
$$ \approx 8\times10^{-27}s $$