Past exam of the particle and nuclear physics course of the University of Cambridge / 2012 / Paper 1 / 1 / a

The static one-pion exchange propagator gives a Yukawa potential proportional to $e^{-m_{\pi }cr/\hslash }/r$. Its characteristic range is therefore the Reduced Compton wavelength,This is an exponential falloff scale, not a sharp interaction cutoff. The ordinary Compton wavelength would introduce an unwanted factor $2\pi$.