Related to Mossbauer Spectroscopy

Jun 2018
Hello friends,

Want to understand the classical theory and quantum theory for Mossbauer effect.
Can anyone help to understand the following equation for radioactive nucleus,
as a classical oscillator with frquency w, the vector potential is given by
A(t) = A(0)exp(-vt) exp(i(wt-kxo))
where v --> damping coefficient, which is half natural width of the excited state