Griffiths Introduction to Elementary Particles · Problem 10.5

Weak Interactions — David J. Griffiths

Physics — QFT · neutron-decay-energy-limits

Problem

Work out the algebra for the neutron decay calculation, deriving the limits on the

E_2

integral from equation (10.53) and the approximation in equation (10.61):

J \cong \frac{4}{c^2} E\sqrt{E^2 - m_e^2 c^4}[(m_n - m_p)c^2 - E]^2

Expanding to lowest order in the small parameters

\epsilon

\delta

\eta

\phi

defined in equation (10.60).