Griffiths Introduction to Elementary Particles · Problem 10.20

Weak Interactions — David J. Griffiths

Physics — QFT · z0-lifetime-estimation

Problem

Estimate the lifetime of the

Z^0

. [Hint: Calculate the decay rate

\Gamma_Z

for

Z^0 \to f + \bar{f}

, summing over all allowed final states (quarks and leptons), and use

\hbar\Gamma_Z

to obtain

\hbar\Gamma_Z \approx 2.5

GeV.]