Comment on "Quantum mechanical versus semiclassical tunneling and decay times"

Abstract

Shegelski, Kavka, and Hynbida have developed a method for calculating the lifetime of a particle initially localized in a potential well exactly quantum mechanically by employing a heuristic expression for the lifetime <t>. Their method allows for the inclusion of a bound state, and their results for tunneling through a centrifugal barrier demonstrate the major role that bound states play in determining the lifetime. In this comment, I show that one can greatly simplify the analysis by calculating <t^2>^(1/2) instead. Results obtained are exact when no bound state is present. In the presence of a bound state the results are only approximate but still illustrate the influence that the presence of a bound state has on the lifetime.