A neutron with kinetic energy T= 25 eV strikes a stationary deuteron (heavy hydrogen nucleus). Find the de Broglie wavelengths of both particles in the frame of their centre of inertia.
Substitution gives λ'=8.6 pm
Since the momenta are equal in the CM frame the de Broglie wavelengths will also be equal.
If we do not assume Md≈2Mn we shall get
