Quantum time scales in alpha tunnelingN. G. Kelkar1, H. M. Castañeda1, 2 and M. Nowakowski1
1 Departamento de Fisica, Universidad de los Andes - Cra. 1E No. 18A-10, Bogota, Colombia
2 Max-Planck-Institut für Kernphysik - Saupfercheckweg 1, 69117 Heidelberg, Germany, EU
received 4 October 2008; accepted in final form 19 December 2008; published January 2009
published online 30 January 2009
The theoretical treatment of alpha-decay by Gamow is revisited by investigating the quantum time scales in tunneling. The time spent by an alpha-particle in front of the barrier and traversing it before escape is evaluated using microscopic alpha-nucleus potentials. The half-life of a nucleus is shown to correspond to the time spent by the alpha knocking in front of the barrier. Calculations for medium and super heavy nuclei show that from a multitude of available tunneling time definitions, the transmission dwell time gives the bulk of the lifetime of the decaying state, in most cases.
03.65.Xp - Tunneling, traversal time, quantum Zeno dynamics.
21.10.Tg - Lifetimes, widths.
23.60.+e - decay.
© EPLA 2009