Griffiths Introduction to Elementary Particles · Problem 6.1

The Feynman Calculus — David J. Griffiths

Physics — QFT · mean-lifetime-decay-rate

Problem

Show that the mean lifetime

\tau

of a particle is the reciprocal of its decay rate

\Gamma

\tau = \frac{1}{\Gamma}

[Hint: Use equations (6.1) and (6.2).]